RADI
LARIA
VOLUME 19
JULY 2001
NEWSLETTER OF THE INTERNATIONAL ASSOCIATION OF RADIOLARIAN PALEONTOLOGISTS ISSN: 0297.5270
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INTERRAD International Association of Radiolarian Paleontologists A Research Group of the International Paleontological Association
Officers of the Association President
Past President
PETER BAUMBARTNER
JOYCE R. BLUEFORD
Lausanne, Switzerland
[email protected]
California, USA
[email protected]
Treasurer ELSPETH URQUHART
Secretary
JOIDES Office Department of Geology and Geophysics University of Miami - RSMAS 4600 Rickenbacker Causeway Miami FL 33149 Florida U.S.A.
JONATHAN AITCHISON Department of Earth Sciences University of Hong Kong Pokfulam Road, Hong Kong SAR, CHINA Tel: (852) 2859 8047 Fax: (852) 2517 6912 e-mail:
[email protected]
Tel: 1-305-361-4668 Fax: 1-305-361-4632 Email:
[email protected]
Working Group Chairmen Paleozoic
Cenozoic
PATRICIA, W HALEN, U.S.A.
A NNIKA SANFILIPPO California, U.S.A.
[email protected]
[email protected]
Mesozoic
Recent
RIE S. HORI Matsuyama, JAPAN
DEMETRIO BOLTOVSKOY Buenos Aires, ARGENTINA
[email protected]
[email protected]
INTERRAD is an international non-profit organization for researchers interested in all aspects of radiolarian taxonomy, palaeobiology, morphology, biostratigraphy, biology, ecology and paleoecology. INTERRAD is a Research Group of the International Paleontological Association (IPA). Since 1978 members of INTERRAD meet every three years to present papers and exchange ideas and materials INTERRAD M EMBERSHIP : The international Association of Radiolarian Paleontologists is open to any one interested on receipt of subscription. The actual fee US $ 15 per year. Membership queries and subscription send to Treasurer. Changes of address can be sent to the Secretary. B IBLIOGRAPHIES: The bibliographies are produced by the Secretary. Any suggestion, reprints of articles and details of omission should be sent to him directly. Please send reprints of any radiolarian article to the Secretary this facilitate the edition of forthcoming bibliographies.
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RADIOLARIA Newsletter of the International Association of Radiolarian Paleontologists ISSN: 0297-5270
VOLUME 19
JULY 2001
Edited by Jonathan Aitchison
CONTENTS President’s address....................................................................................................................................4 Editors note ...............................................................................................................................................4 Past and current radiolarian investigations in Brazil……………………… Valesca Portilla Eilert...............5 www.radiolaria.org …………………………………………………… Jane Karine Dolven ..................6 Announcements of Publications: New book on radiolarians…………………………………………….. 7 Conference and Symposia announcement …………………………………………………………….... 8 Radiolarian Bibliography 2000-2001………….………………………... Jonathan Aitchison…………19
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PRESIDENTS ADDRESS
EDITORS NOTE
contributions many would lose touch of what is happening in the rad world. Humbug to those of you who simply prefer to receive and never contribute! Regards
A year has passed since the last issue of RADIOLARIA. Doubtless many of you enjoyed the meeting successfully organized by Paula in Blairsden. We all thank her and her helpers for the months of hard work. Thanks to all of you who contributed copies or details of publications, working group reports and other material to this issue. Without your
Jonathan Aitchison
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PAST AND CURRENT RADIOLARIAN INVESTIGATIONS IN BRAZIL Valesca Portilla Eilert – Laboratório de Micropaleontologia (LabMicro)/Depto de Geologia/IGEO/UFRJ – Cidade Universitária, Ilha do Fundão - CEP 21949-900, Rio de Janeiro, RJ.E-mail:
[email protected]
Micropaleontological surveys in Brazilian basins traditionally focused on foraminifers, calcareous nannofossils, ostracods and palynomorphs. These calcareous and organic walled fossil groups have successfully been applied to investigate several geological problems. This fact can explain, at least in part, why there are very few detailed radiolarian studies in Brazil. Likewise, the laboratory procedures normally employed to the other groups, most of the times resulted in the false statement that the samples are “barren” concerning the presence of radiolarians. Radiolarians in Brazil have been studied by micropaleontologists from the Universidade Federal do Rio Grande do Sul/ UFRGS and Universidade Estadual Paulista/UNESP, as well as by experts from PETROBRAS, the brazilian oil company. The first reports, in the decade of 60’s, were isolated, imprecise and had very restricted circulation. During the 80s, Prof. S. B. Kotzian and collaborators (UFRGS) developed the pioneer academic radiolarian studies in Brazil. Since then, the number of citations had increased in Brazilian geo-scientific literature. After analyzing the list of publications, we can observe that citations related to radiolarians from Pelotas (Pleistocene-Holocene interval) and Campos (middle Cretaceous interval) basins predominate. Most of the publications simply mention their occurrence, without taking into account the species identification. Academic surveys, presenting detailed taxonomical studies, were carried out only on radiolarians collected in Pelotas Basin. In the next decade, radiolarians were recorded in Early Cretaceous cherts from Sanfranciscana Basin. Although poor preservation prevented detailed taxonomical study until this moment, detailed studies are needed since the depositional environment is up till now interpreted as essentially continental. Paleozoic deposits should also be investigated in the future, as a suspicious occurrence of radiolarian in Permian rocks from the Irati Formation, Paraná Basin, was reported. Besides taxonomical studies, radiolarians have been applied to the investigation of paleotemperatures, paleocirculation, identification of bioevents associated with volcanism, and in gathering paleobathymetric data associated to the study of the geological evolution of the South Atlantic ocean. It can be pointed out that until now there is no biostratigraphical zonation based on radiolarians for any of the Brazilian sedimentary basins. At present, the first detailed studies on biostratigraphy are in progress: 1) Post-Doc project: ”Late Cretaceous radiolarians from Santos Basin (southeast Brazilian Continental Margin): biostratigraphy and paleoecology” by Valesca Eilert, at the Laboratory of Micropaleontology (LabMicro)/Universidade Federal do Rio de Janeiro(UFRJ), Rio de Janeiro, RJ. 2) Ph.D. thesis: ” Late Cretaceous radiolarians palaeocenography and biostratigraphy of the equatorial Atlantic Ocean (ODP Legs 108 and 159 and DSDP Legs 75 and 80)” by Simone Baecker Fauth and 3) Ph.D. thesis: ”Mid-cretaceous radiolarians from Campos Basin (southeast Brazilian Continental Margin): biostratigraphy and paleoecology” by Vladimir de Souza, both at the Graduate Course in Geosciences/Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS. In a near future, as a consequence of the progressive exploration of deep and ultra-deep water deposits in the Brazilian marginal basins, it is natural that radiolarian studies would demonstrate its usefulness as a valuable micropaleontological tool. This would be especially true where the calcareous and organic walled microfossil groups may be absent or present, but of no application, as have been documented recently in some Cretaceous intervals.
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www.radiolaria.org
The idea of making www.radiolaria.org came up during late spring in 2000. As a radiolarian researcher I saw the use of having an online database where I could find information (images, descriptions, references, synonyms etc.) about radiolarians. Previously I had been using various documents on my computer to keep my information at hand, and I knew of several other researchers with their own set of documents. Now that the Internet is so readily available, would it not be nice to gather all the information in one place where we could all access them easily at any time. As luck would have it my partner Hans is a web developer so we decided to make a prototype of the system and acquire the domain name www.radiolaria.org. We started with gathering information from the radiolarian research community about previous thoughts and ideas for such a system. During development we asked a few fellow researchers to have a look and give us feedback and suggestions, which was a great help. The prototype of www.radiolaria.org was presented at the Interrad-meeting in California September 2000, where we received new tips, useful feedback and a lot of encouragement to keep up the work. www.radiolaria.org contains so far the following sections: · „What are Radiolarians‰ contains a short introduction about radiolarians. · „Mystery Rad of the Month‰. Under this section it is possible to post a picture and information about an unknown radiolarian species and let the radiolarian community share their opinions and suggestions to which species this may be. · „Archive‰ includes (scanned) plates with captions of important taxonomic publications. Four papers have so far been made available. These are Benson (1966), Cleve (1899, 1901) and Jørgensen (1905). · „Web links‰ contain links to other online radiolarian resources. · „News‰ keeps you updated on what is happening within www.radiolaria.org, and in the Radiolarian community in general. · „Rad art‰ shows pictures of radiolarian models made in white clay by a Swedish artist called Eva Bjerke. · We are continuously working on adding information (images, descriptions, references, synonyms, and links to other online resources) about species from different periods. So far there are 24 species (spumellarians, nassellarians and phaeodarians) in the system if you look under Quaternary > Holocene (Recent) > Nordic Seas. The idea behind Radiolaria.org is that anybody can contribute with their expertise, i.e. add information about species with images, descriptions, references, synonyms, and links etc. Under each species there is also a discussion forum where we can post and exchange ideas, opinions, comments etc. Anyone has the opportunity to contribute from any web browser any time. Hopefully this will be an easy way of sharing and exchanging data between all radiolarian researchers. The future of www.radiolaria.org: When the system has reached an acceptable level of usefulness and stability, we will place the ownership and control of the whole system (content, code, domain name) with the radiolarian community. We believe that this can be achieved by electing a research institution (maybe at the next Interrad-meeting in Switzerland 2003?) that will be responsible for maintaining www.radiolaria.org and coordinating further development. The elected institution has the following obligations: (1) Ensure that the work continues. (2) Keeping the site accessible and free for anyone to use. (3) Give someone else within the radiolarian community the opportunity to take over if they decide to stop working on the site, under the outlined conditions. Jane Karine Dolven
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Announcements of Publications New Book on radiolarians De Wever, P., Dumitrica, P., Caulet, J., Nigrini, C., Caridroit, M. Radiolarians in the Sedimentary Record P. De Wever, Laboratoire de Géologie, Muséum National d'Histoire Naturelle, Paris, France, P. Dumitrica, Bern, Switzerland, J. P. Caulet, Laboratoire de Géologie, Muséum National d'Histoire Naturelle, Paris, France, C. Nigrini, Canmore, Canada and M. Caridroit, Laboratoire de Paléontologie, Université de Lille, France Radiolarians in the Sedimentary Record presents the current state of knowledge on fossil radiolarians, as well as a new integrated taxonomic system at the family level. This book provides comprehensive coverage of the fossil record of these unicellular organisms, and discusses their important role in the history of the Earth and the development of the biosphere. The use of fossilised radiolaria in solving geologic problems is also examined. Seven chapters by leading researchers in the field cover the biology, morphology, taxonomy, taphonomy and biostratigraphy of radiolarians. The appendix provides detailed sampling and processing techniques of radiolarian skeletons and an extensive glossary of terms. Contents: Living Radiolarians: Cellular Organisation " Biology " From Plankton to Sediment: Radiolarians in the Water Column " Vertical Flux of Radiolarians " Radiolarian Dissolution " Radiolarians in Bottom Sediments " Radiolarians as Palaeoenvironmental Markers " From Sediments to Rocks: Diagenesis of Biogenic Silica " Epigeny " Radiolarian Rich Rocks " Radiolarian Rocks and Organic-rich Deposits " Taxonomy of Radiolaria: Historical Perspectives " Towards a New Classification " Radiolarian Taxonomy " Stratigraphy: Introduction " Palaeozoic Stratigraphy " Mesozoic Biostratigraphy " Cainozoic Stratigraphy " Evoloution: Origin of Radiolaria " Evolutionary Trends " Evolutionary Crises and Major Boundaries Readership: Researchers and graduates in the fields of sedimentology and palaeontology and professionals in the oil industry. March, 2001 / 524 pp / Cloth / 90-5699-336-4 100 halftones, 135 line illus. EUR 126 / GBP £75 / USD $115 All prices are tentative and subject to change. Any discounts will be applied upon checkout. Gordon and Breach Science Publishers Member of Taylor & Francis Group
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Variscides-Craton-Uralides: Linkage between Orogenic and Intraplate Processes EUROPROBE Devonian-Triassic “Time-Slice” Symposium Moscow 28-29 October 2001 EUROPROBE-sponsored meetings in 2001 comprise a series of four “time-slice” orientated symposia crossing the bounds of EUROPROBE projects and representing the culmination of these projects. The “time-slice” symposia are aimed at identifying links between Earth evolution events occurring synchronously in Europe, but in different geological provinces, and thereby elucidating the possible genetic links and feedback paths among the underlying asthenospheric-lithospheric processes. The Devonian-Triassic in Europe was in general a time of convergence at its margins, with consolidation of accreted orogenic belts, contemporaneous with plume activity, magmatism, and thermo-extensional destabilisation in its interior. Accordingly, the EUROPROBE Devonian-Triassic “Time-Slice” Symposium combines aspects of the EUROPROBE Urals, GeoRift, and TESZ projects. It will take place in Moscow 28-29 October 2001, immediately prior to the “7 th Zonenshain International Conference on Plate Tectonics”. The Variscides-Craton-Uralides: Linkage between Orogenic and Intraplate Processes Symposium invites contributions documenting changes in tectonic style from Devonian until Triassic times in Europe’s various geological provinces in order to unravel the competing roles of governing processes in time. While documentation of the age and spatial correlation of lithospheric structures and tectonic events is a key goal of the symposium, the geophysical dimension of mapping lithosphere evolution patterns in time and space is also important. Results of the symposium will contribute to an integrated volume of EUROPROBE research to be published in 2002. Convenors of the EUROPROBE-Moscow Symposium are R.A. Stephenson (
[email protected]), A. PerezEstaun (
[email protected]), and T. Pharaoh (
[email protected]). Interested participants are invited to contact one of the above by e-mail with the title of a proposed contribution by 30 June 2001 (?) and an abstract by 31 August (?). Oral as well as poster presentations are welcome, but the total number of presentations and the number of participants will be severely limited and based on the choices of the convenors. Participants may qualify for (limited) financial assistance from the European Science Foundation (via the EUROPROBE programme) and are encouraged to stay in Moscow after the EUROPROBE Symposium and contribute to the “7 th Zonenshain International Conference on Plate Tectonics” that immediately follows. Information on the latter can be found at www.nsu.ru/science/rsgsgt/tsr.htm.
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Second Circular INTERNATIONAL TECTONIC SYMPOSIA Moscow _ St. Petersburg, Russia October 28 - November 3, 2001
Part I. Moscow EUROPROBE WORKSHOP Variscides-Craton-Uralides: Linkage between Orogenic and Intraplate Processes October 28-31, 2001
7-th ZONENSHAIN INTERNATIONAL CONFERENCE ON PLATE TECTONICS GENERAL PROBLEMS OF TECTONICS October 30-31, 2001 RUSSIAN ACADEMY OF SCIENCES (RAS) Ministry of Natural Resources of the Russian Federation (MNR RF) Ministry of Industry, Science and Technology of the Russian Federation (MIST RF) P.P.Shirshov Institute of Oceanology RAS Institute of the Lithosphere of Marginal Seas RAS All-Russia Research Institute for Geology and Mineral Resources of the World Ocean "VNIIOkeangeologia" Tectonic Society of Russia (TSR) Interdepartmental Tectonic Committee (ITC) Moscow State University (MSU) State Scientific Centre of Arctic and Antarctic Research Institute (SSC AARI) Alfred Wegener Institute GEOMAR Research Center for Marine Geosciences EUROPROBE _ European Science Foundation
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DEAR COLLEAGUES! The Organizing Committee invites you to take part in the 7-th Zonenshain International Conference on Plate Tectonics THE ORGANIZING COMMITTEE Chairman Co-chairman Co-chairman -
V.E.Khain (ILRAN) I.S.Gramberg (VNIIOceangeology) J.Thiede (Alfred Wegener Institute, Germany)
Vice-chairman - N.A.Bogdanov (ILRAN) Vice-chairman - L.I.Lobkovsky (IORAN) Vice-chairman - G.A.Cherkashev (VNIIOceangeology) Members of the Organizing Committee: G.E.Grikurov (VNIIOceangeology) L.V.Dmitriev (GEOCHI) W.-C.Dullo (GEOMAR, Germany) H.Kassens (Schmidt Laboratory) A.L.Knipper (GIN) N.V.Koronovsky (MSU) M.I.Kuzmin (Inst. of Geochemistry Siberian Branch RAS) A.P.Lisitsin (IORAN) E.G.Mirlin (Vernadsky State Museum RAS) A.M.Nikishin (MSU) S.M.Pryamikov (AANII) E.V. Shipilov (Res. Inst. of Marine Geophysics) Executive Secretary – V.E.Verzhbitsky (ILRAN) You are welcome to address questions and wishes to the Secretariat of the Organizing Committee to Verzhbitsky Vladimir E. Our address is Institute of the Lithosphere of Marginal Seas RAS 22, Staromonetny per., 109180 Moscow Russia Tel.: 007 (095) 953 55 88 FAX: 007 (095) 953 55 90 E-mail:
[email protected],
[email protected]
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The Conference will consist of the following sections: Moscow. October 30-31, 2001
1. 2. 3. 4. 5. 6. 7. 8.
Mid-Ocean Ridges. Interdisciplinary Approach. Ophiolites. Contemporary view. Plate Tectonics and Deep Earth Dynamics. Plumes (their role in the tectonics and magmatism) and Intraplate Tectonics. Tethys and Peritethys: Interaction of Two Systems. Paleogeodynamic Reconstructions. Active and Passive Margins. Collisional Belts. Transform Faults and Triple Junctions.
Workshop 1: Radiolaria: from High Latitudes to Equator, Paleoreconstructions. Workshop 2: Tectonics of the Sea of Okhotsk Region and Kamchatka.
Moscow. 28-29 October 2001 EUROPROBE WORKSHOP
VARISCIDES-CRATON-URALIDES: LINKAGE BETWEEN OROGENIC AND INTRAPLATE PROCESSES http://www.nsu.ru/science/rsgsgt/tsr.htm
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CALL FOR ABSTRACTS The deadline of submitting abstracts is August 1, 2001 by e-mail (
[email protected],
[email protected]) as attached file. The mode of submission of abstracts is as follows: no more than 500 words in WinWord (PC) (any version), Times New Roman type, with single interval. References should be included in the text in brackets. A separate reference list is not accepted! Type close to the left margin, no hyphened words. The spacing from the top, bottom, left side and right side must be 2 cm. Indent each paragraph 0,5 cm. Spacing: one blank line to be left between the title and the authors’ names, two blank lines to be left between organization address and the text of the paper. The title - 12 bold The authors -12 normal Organization, e-mail or fax – 10 normal The text – 10 normal
Example: Tectonics of the Northern Pacific Ocean M.Brown Organization, address, e-mail or fax
Text of abstracts
NOTE: Please, notify the number and the full name of your section at the end of your abstract. Mention the mode of your presentation (oral or poster), full name, your telephone number and e-mail. The Organizing Committee takes up to edit the text, to reject the abstract in case they are not drawn up properly or if they do not correspond to the themes of the sections of the Conference. REGISTRATION FEE 200 US$ for full members, 60 US$ for accompanying persons, 50 US$ for student members. Registration payments from each participant will be accepted during the registration upon arrival. The registration fee includes a volume of abstracts, a personal badge, and refreshments during the breaks. Participants of both Conferences (in Moscow and St Petersburg) pay their fee only once. Information and e-mail addresses for those who intend to take part in the EUROPROBE meeting “Variscides-Craton-Uralides: Linkage between Orogenic and Intraplate Processes” can be found in the attached circular. PROGRAM of the Conference will be circulated with the Third Circular sent by separate message before the conference beginning.
You are welcome to send your questions and comments to the Secretariat of the Organizing Committee to Vladimir E. Verzhbitsky.
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FINAL REGISTRATION FORM (to be sent before September 1, 2001) Please send us xerox copy of the first passport page by fax or mail – which is necessary for obtaining official invitation to the Russian Federation Participant: First name____________Given name_____________ Name____________________ Sex: Male Female DEGREE_____________________________________________________________ ORGANIZATION______________________________________________________ _____________________________________________________________________ POSITION____________________________________________________________ ADDRESS: Street________________City________________Code______________ COUNTRY___________________________________________________________ CITIZENSHIP_________________________________________________________ PASSPORT NUMBER__________________EXPIRY DATE___________________ DATE OF BIRTH______________________________________________________ ARRIVAL IN RUSSIA (day, month, year)__________________________________ DEPARTURE FROM RUSSIA (day, month, year)____________________________ PERIOD OF STAY IN RUSSIA (days)_____________________________________ CITIES TO BE VISITED IN RUSSIA______________________________________ PLACE OF OBTAINING VISA (country and city, where there is an embassy or consulate of Russia)_____________________________________________________ If you are vegetarian, please indicate ACCOMMODATION: double single PHONE______________________ FAX_________________________ E-MAIL______________________ TITLE OF PRESENTATION______________________________________________________ SECTION OF THE CONFERENCE________________________________________________________ Presentation: oral poster If you need any special equipment for your presentation, please indicate______________________________________________________________ EVENTS YOU INTEND TO PARTICIPATE: [ ] Conference “General Problems of Tectonics” [ ] EUROPROBE Workshop [ ] St Petersburg Conference Accompanying person: First name_____________Given name______________ Name__________________ Sex: Male Female DEGREE_____________________________________________________________ ORGANIZATION______________________________________________________ _____________________________________________________________________ POSITION____________________________________________________________ ADDRESS: Street________________City_______________Code_______________ COUNTRY___________________________________________________________ CITIZENSHIP_________________________________________________________ PASSPORT NUMBER_________________EXPIRY DATE____________________ DATE OF BIRTH___________________ ARRIVAL IN RUSSIA (day, month, year)______________________________ DEPARTURE FROM RUSSIA (day, month, year)________________________ 13
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PERIOD OF STAY IN RUSSIA (days)_________________________________ CITIES TO BE VISITED IN RUSSIA__________________________________ PLACE OF OBTAINING VISA (country and city, where there is an embassy or consulate of Russia)_________________________________________________ If you are vegetarian, please indicate ACCOMMODATION: double single IMPORTANT!!! Please consult the Russian representation where you intend to apply for a visa whether they will: [ ] accept a fax (or written) invitation from the Organizing Committee [ ] require a formal visa invitation issued by the local branch of the Russian Ministry of Foreign Affairs
Contact person and address: Institute of the Lithosphere of Marginal Seas RAS 22, Staromonetny per., 109180 Moscow Russia Phone: (095) 953-55-88 Fax: (095) 953-55-90 E-mail:
[email protected],
[email protected] Vladimir E. Verzhbitsky
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SECOND CIRCULAR
INTERNATIONAL TECTONIC SYMPOSIA Moscow - St. Petersburg, Russia
28 October - 3 November 2001 Part II. St. Petersburg, 1-3 November, 2001
«POLAR REGIONS OF THE EARTH - GEOLOGY, TECTONICS, RESOURCE SIGNIFICANCE, NATURAL ENVIRONMENT» «EUROPROBE» SYMPOSIUM «PLATE TECTONICS IN ARCHEAN AND EARLY PROTEROZOIC: GEOLOGICAL AND GEOPHYSICAL DATA» POST-CRUISE WORKSHOP «KNIPOVICH-2000»
Ministry of Natural Resources of the Russian Federation Ministry of Industry, Science and Technology of the Russian Federation Russian Academy of Sciences All-Russia Research Institute for Geology and Mineral Resources of the World Ocean "VNIIOkeangeologia" All-Russia Geological Institute VSEGEI Institute of lithosphere of the Russian Academy of Sciences (ILRAS) Tectonic Society of Russia
EUROPROBE - European Science Foundation Org an izin g Co mmit t ee C HAIRMAN -
IGOR S. GRAMBERG (VNIIOKEANGEOLOGIA)
Co-chairmen -
Viktor E. Khain (ILRAS) Rinat R. Murzin (Ministry of Natural Resources) Andrei F. Morozov (Ministry of Natural Resources)
Deputy chairmen -
Oleg V. Petrov (VSEGEI) Nikita A. Bogdanov (ILRAS) 15
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Members -
Georgy A. Cherkashev (VNIIOkeangeologia) Garrik E. Grikurov (VNIIOkeangeologia) Evgeni A. Kiselev (VSEGEI) Alexander P. Lisitsyn (Shirshov Institute) Gleb B. Udintsev (Vernadsky Institute) Evgeny E. Musatov (ILRAS – St. Petersburg) Vladimir M. Kotlyakov (RAS Scientific Council for the Arctic and Antarctic Research) Vladimir D. Kruykov (PMGRE) Gennadi S. Kazanin (MAGE) Ivan E. Frolov (AARI)
Secretary -
Elena A. Miloradovskaya (VNIIOkeangeologia) The Conference is planned to include three main sections:
I.
THE ARCTIC
1. Structure and evolution of the Arctic Ocean and adjacent land 1.1. Deep-sea basins, oceanic ridges and rises 1.2. Circum-Arctic continental shelf 1.3. Continental land (controversial tectonic issues and ideas) 2. Oil and gas potential, gas hydrates
3. Mineral resources II.
THE ANTARCTIC
1. Structure and evolution of Antarctica and adjacent seas Precambrian of East Antarctica
1.1. 1.2.
1.3.
Phanerozoic mobile belts Sedimentary basins
2. Antarctic mineral resources – prospects versus realities
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ENVIRONMENT AND GLOBAL CHANGES IN THE POLAR
REGIONS (GLACIATIONS, CLIMATE EXTREMES, MODERN PROCESSES, ENVIRONMENTAL PROTECTION) CALL FOR ABSTRACTS The authors are strongly encouraged to submit abstracts before 1 August to enable the Organizing Committee with editing and publishing of the volume. The abstracts must be submitted in electronic format (any version of World) and not exceed 500 words (including references) without illustrations. Left margin - 3 cm, right margin - 1 cm . Indent each paragraph 0.5 cm. Spacing – between title and authors names –1, between authors names and organization’s data-1, between organization’s data and text – 2. Title – 12 Times New Roman, bold Authors -10 Times New Roman Organization, e-mail or fax – 10 Times New Roman The text – 10 Times New Roman Example: Devonian orogenesis in Northern Yukon: implications for Paleozoic paleogeography and tectonic evolution» L.Lane Organization, address, e-mail or fax
Text of abstract NOTE: Organizing Committee reserves the a right to edit the abstracts for better clarity. The abstracts of intended presentations received by the indicated deadline will be included in the program and reproduced at the conference as working documents. The abstracts volume will be edited and printed within a short time after the conference. It will include only the abstracts of presentations actually given at the conference by registered participants in the form of oral or poster contribution. ACCOMODATION: will be in comfortable *** hotel nearby the conference site. Price: 30 - 40 USD per night REGISTRATION FEE 200 USD for active participant, 60 USD for accompanying person, 50 USD for students. Registration fee includes transportation from/to airport, registration of visa invitations to foreign participants in the Ministry of Foreign Affairs, volume of abstracts, personal badge, refreshments during conference days and participation in the banquet. Payment will be accepted upon arrival in course of registration. Participants of both Conferences (in Moscow and St. Petersburg) pay their fee only once. PROGRAM of the Conference will be circulated with the Third Circular sent by separate message before the conference beginning.
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FINAL REGISTRATION FORM (please, send before August 1, 2001) for those who needs an official invitation to the Russian Federation Please, also send us xerox copy of the first passport page by fax or mail Participant: First name__________Given name___________ Name__________________ Sex male female ORGANIZATION________________________________________________ ADDRESS: Street________City_________ZIP________ COUNTRY_________ PASSPORT NUMBER_______________EXPIRATION DATE_________________ DATE OF BIRTH______________ PERIOD OF STAY IN RUSSIA_________________ TELEPHONE________________________________ FAX________________________________________ E-MAIL_____________________________________ PLACE WHERE YOU WILL APPLY FOR A VISA___________________________ CITIES TO BE VISITED IN RUSSIA ACCOMMODATION: double single Where you would like to participate? [ ] Main conference [ ] Symposium «EUROPROBE» [ ] Workshop «KNIPOVICH-2000» If you need any special equipment for your presentation, please indicate_______________________________________________________________________ Accompanying person: First name__________Given name___________ Name__________________ Sex male female ADDRESS: Street________City_________ZIP________ COUNTRY_________ PASSPORT NUMBER_______________EXPIRATION DATE_________________ DATE OF BIRTH______________ Phone _______________Fax_____________e-mail___________ ACCOMMODATION: double single Contact person and address: Elena Miloradovskaya VNIIOKEANGEOLOGIA 1, Angliysky av., St. Petersburg 190121, RUSSIA Tel. 7 (812) 114 8218 Fax: 7 (812) 114 1470 e-mail
[email protected]
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Bibliography - 2000-2001
BIBLIOGRAPHY 2000-2001 Jonathan Aitchison
This compilation contains 140 references, mostly covering the 2000-2001 period. (Abstracts from the 2000 INTERRAD meeting are not included – they were published in the conference volume which you received when you attended the meeting). This list of publications has been possible thanks to the collaboration of colleagues who have sent their articles. I am grateful to all of them. If your paper is missing it is probably because you didn’t bother sending me a reprint.
Marine Paleogene in the West Siberian Plate Stratigraphy and Geological Correlation 9: 132-158.
AFANASIEVA, M.S., 2000. New radiolarians of the superfamily Entactinoidea from the Upper Devonian of Timan-Pechora Province, Russia. Paleontological Journal, 34(2): 131-146.
ABSTRACT: The regional stratigraphic scheme suggested for the marine Paleogene deposits in the West Siberian plate is based on investigation results of macro- and microfossils (foraminifers, dinoflagellates, radiolarians, diatomaceous algae, silicoflagellates, Elasmobranchii, ostracodes, pollen, and spores). In the West Siberian plate, like in many structural–facies zones of the East European platform, there was a hiatus in sedimentation at the Cretaceous–Paleogene boundary. The Talitsa Horizon corresponds here to the Danian and Selandian pre- sumably coupled with the initial Thanetian. The lower Lyulin-Vor Subhorizon is dated back t o the late Pale- ocene; the middle Lyulin-Vor Subhorizon is correlated with the Ypresian, and the upper one is attributed to the interval spanning the second half of the Ypresian and Lutetian. The Tavda Horizon of the Bartonian–Priabonian age presumably comprises as well the terminal Lutetian. The Kurgan Beds (s. str.) representing marine facies of the Atlym Horizon correspond in the type area (near the town of Kurgan) to the lower Oligocene. Boundaries o f these lithostratigraphic units are diachronous, since the Paleoarctis in the north and the Tethys in the south were connected with the epicontinental West Siberian sea basin producing an irregular impact on sedimentation in the latter.
ABSTRACT: New radiolarian taxa from the Frasnian of the TimanPechora Province, Russia, belonging to the order Sphaerellaria, superfamily Entactinoidea are described: Moskovistella octoradiata gen. et sp. nov., M. allbororum sp. nov., M. khaini sp. nov., M. mira sp. nov., M. rozanovi sp. nov., M. sincera sp. nov., M. victorialis sp. nov., Astroentactinia rusaevi sp. nov., A. tikhomirovi sp. nov., A. vishnevskayae sp. nov., Helioentactinia gudymovae sp. nov., Borisella maksimovae gen. et sp. nov., B. bykovae sp. nov. and B. mariae sp. nov.
AFANAS’EVA M. S. AND AITCHISON J. C. 2001. Biostratigraphy of the Frasnian Stage by Radiolarian Evidence. Stratigraphy and Geological Correlation 9: 11-19. ABSTRACT: Revising Frasnian radiolarians, we established three new radiolarian zones within this stage. These are the Helenifore gogoense–Retisphaera concinna Zone of the lower Frasnian, Moskovistella allbororum–Ceratoikiscum ukhtensis Zone of the middle Frasnian, and Bientactinosphaera egindyensis–Polyentactinia circumretia Zone of the upper Frasnian.
AL, R.K., ROBERTSON, A.H.F., XENOPHONTOS, C., DANELIAN, T. AND DIXON, J.E., 2000. Tectonic evolution of the Mesozoic Arabian passive continental margin and related ophiolite in Baer-Bassit region (NW Syria). In: I. Panayides, C. Xenophontos and J. Malpas (Editors), Proceedings of the Third international conference on the Geology of the eastern Mediterranean. Ministry of Agriculture, Natural Resources and Environment, Geological Survey Department. Nicosia, Cyprus. 2000. Pages 61-81.
AIELLO, I.W. AND HAGSTRUM, J.T., 2001. Paleomagnetism and paleogeography of Jurassic radiolarian cherts from the Northern Apennines of Italy. Geological Society of America Bulletin, 113(4): 469-481. ABSTRACT: Oriented samples of Jurassic radiolarian chert were collected from the Tuscan domain (continental margin) and the Ligurid domain (oceanic) of the northern Apennines f o r paleomagnetic study to determine the paleogeographic origins o f these rocks. The oceanic rocks are all thermochemically overprinted by a mostly reversed-polarity component of magnetization (B) that was likely acquired during late Miocene regional uplift of the northern Apennines. This component also dominates the lower brittle chert of the Tuscan Cherts, but disappears upsection in the more clay-rich and ductile siliceous marlstones. In addition, the Tuscan Cherts retain an inferred primary magnetization (C), isolated at temperatures between 560 and 660 degrees C, which passes a fold test and shows a polarity stratigraphy. This component indicates a paleolatitude of 11 degrees ± 4 degrees N, and a counterclockwise vertical-axis rotation of 29 degrees ± 9 degrees with respect to the southern Alps of Italy, of 49 degrees ± 8 degrees with respect to Africa, and of 91 degrees ± 8 degrees with respect to Eurasia. Our results suggest that the Tuscan domain was farther south than other deep-water continental margin sections of Adria, and that transcurrent faulting might have played a significant role in the orogenic evolution of the northern Apennines.
ABSTRACT: The rift, drift, and closure history of an ocean basin in the Baer-Bassit area, NW Syria, exemplifies the evolution o f Neotethys at the western end of the "ophiolitic crescent". Mesozoic (Middle Jurassic to Lower Maastrichtian) platform carbonates are overthrust by allochthonous Neotethyan units of continental marginal and oceanic origins. Emplaced successions, restored from within the Baer-Bassit Melange, begin with deep-sea radiolarian cherts, pelagic limestones and alkaline volcanics of Late Triassic age. These are overlain by mainly non-calcareous deep-water sediments of distal passive margin affinities. Also present are alkaline volcanics that are interpreted as seamounts formed outboard of the Arabian passive margin. Interbedded radiolarian cherts are dated as Pliensbachian-Bajocian. Structurally above the melange is the dismembered Upper Cretaceous Baer-Bassit ophiolite that includes plutonics, sheeted dykes and volcanics (including high-Mg boninite-type lavas). Geochemical evidence from the extrusives suggests a supra-subduction zone origin for the BaerBassit ophiolite, similar to both the Troodos and Hatay ophiolites in the easternmost Mediterranean region. The Baer-Bassit plutonics are structurally underlain by a well developed metamorphic sole (up to 300 m thick), for which the protoliths are mainly alkaline extrusives, similar to volcanics within the melange. The origin of the metamorphic sole is related to overthrusting of the young, hot BaerBassit ophiolite over Neotethyan oceanic crust, including sediments, followed by frontal accretion of deep-sea sediments and volcanics. The entire assemblage, including passive margin units, was then imbricated and emplaced onto the Arabian margin in Mid Maastrichtian time, mainly towards the SE, as shown by structures
AKHMET’EV M. A., ALEKSANDROVA G. N., AMON E. O., BENIAMOVSKII V. N., BUGROVA E. M., VASIL’EVA O. N., GLEZER Z. I., ZHELEZKO V. I., ZAPOROZHETS N. I., KOZLOVA G. E., NIKOLAEVA I. A., ORESHKINA T. V., PANOVA L. A., RADIONOVA E. P., STREL’NIKOVA N. I., AND YAKOVLEVA A. I. 2001. Biostratigraphy of the 19
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in both the melange (e.g. duplexes) and the metamorphic sole (e.g. stretching lineations). Regional evidence (e.g. SE Turkey, Oman) suggests that latest Cretaceous ophiolite emplacement predated collision of the Eurasian and African plates. Following emplacement and short-lived conglomerate deposition, the area was onlapped by Late Maastrichtian-Early Tertiary shallow to deeper marine carbonates, deposited on an unstable submerged shelf. This transgression was followed by Mid-Late Eocene to Miocene deformation, related to suturing of Neotethys, probably including updoming of the Jabal Aqraa Mesozoic carbonate platform in northern Baer-Bassit. Post collisional, shallow-marine deposition began in the Miocene, followed by a regression in the Late Pliocene. Neotectonic structures in Baer-Bassit mainly relate to strike-slip (mainly left-lateral) and normal faulting, linking the Cyprus active margin with the Dead Sea fault system to the east.
Campanian and Paleocene flysch deposits of the Raca Subunit, Magura Nappe, Polish Western Carpathians. The Late Albian foraminifers derived from the sourer: area located at the NW margin of the Magura Basin, whereas the Cenomanian Foraminifers derived from the SE periphery of the basin. The presence of such microfauna is interpreted as an occurrence of a submarine plateau with pelagic deposition, under lower neritic-upper bathyal depths in the marginal parts of the Magura Basin, during the Late Albian-Early Cenomanian. This assumption was used for reconstruction of the Late AlbianEarly Cenomanian paleogeography of the Magura Basin.
BAK, M. AND SAWLOWICZ, Z., 2000. Pyritized radiolarians from the mid-Cretaceous deposits of the Pieniny Klippen Belt - a model of pyritization in an anoxic environment. Geologica Carpathica, 51(2): 91-99.
ANDERSON, O. R., NIGRINI, C., BOLTOVSKOY, D., TAKAHASHI, K., AND SWANBERG, N. R., 2001 in press. Class Polycystina. In: Lee, J. J. (ed.) The Second Illustrated Guide to the Protozoa. Society of Protozoologists, Lawrence, KS.
ABSTRACT: Excellently preserved, pyritized radiolarian skeletons have been found within the Upper Cenomanian deposits in the Pieniny Klippen Belt (PKB-Carpathians, Poland). On the basis of a study of their chemical composition, structure of replacing skeletons and exceptional preservation of all morphological details, we propose a new model where the pyritization process took place not in sediment but while the radiolarian skeletons were suspended in the anoxic water column. The radiolarians rich in organic matter, sinking through the upper (iron-rich) part of an anoxic water column, became the sites of organic matter decomposition and enhanced bacterial sulphate reduction. Dissolved iron in this zone diffused into the radiolarians and precipitated as iron sulphides replacing the opaline skeletons. This process was controlled by the rates of opal dissolution and of bacterial sulphate reduction, and the availability of dissolved iron. The preservation of radiolarians in the Upper Cenomanian deposits from different depth sub-basins of the PKB was compared. We found that the extent of pyritization and preservation of radiolarian skeletons may be dependent on the depth of the basin and the position of the oxic-anoxic interface.
AUBOURD C., DANIEL J-Y.., DE WEVER P. (coord.) 2000.Problèmes résolus de Sciences de la Terre et de l‚Univers. Vuibert 360 pages. BABAIE, H.A., GHAZI, A.M., BABAEI, A., LA, T.T.E. AND HASSANIPAK, A.A., 2000. Geochemistry of arc volcanic rocks of the Zagros Crush Zone, Neyriz, Iran. Journal o f Asian Earth Sciences. 19(1-2): 61-76 ABSTRACT: The northeastern margin of the Tethyan Neyriz ophiolite complex in southwestern Iran is tectonically juxtaposed under cataclastically-deformed island arc volcanic-volcaniclastic rocks. We document this arc component of the Zagros Crush Zone in the Neyriz area, and describe its petrographic and geochemical characteristics. The arc unit which we call the Hassanabad Unit, i s tectonically intercalated with Cretaceous limestone in the cataclastic shear zone around the Hassanabad pass north of Neyriz. Analyses of the distributions of the major, rare earth and other trace elements in the volcanic rocks of the Hassanabad Unit reveal a dominantly calc-alkaline island arc composition. Volcanogenic sandstone and sedimentary breccia, with clasts of basalt, andesite and diorite, are cataclastically intercalated with pillowed calcalkaline island arc volcanic rocks, pelagic limestone and radiolarian chert. Trace element geochemistry corroborates the petrographic evidence that the poorly-sorted and angular volcanogenic sediments were derived locally from the island arc volcanic and intrusive rocks. The emplacement of the volcanic arc rocks adjacent to the thrust sheets of the crustal and mantle sequences of the Neyriz ophiolite was probably a result of subduction-related processes during closure of the Tethys ocean during the Late Cretaceous. (C) 2001 Elsevier Science Ltd. All rights reserved.
BAK, K., UCHMAN, A. AND BAK, M., 2000. Agglutinated foraminifera, radiolaria and trace fossils from upper Cretaceous deep-water variegated shales at Trawne Stream, Grajcarek unit, Pieniny Klippen Belt, Carpathians, Poland. Bulletin of the Polish Academy of Sciences Earth Sciences, 48(1): 1-32. ABSTRACT: The age and palaeoenvironment of the Upper Cretaceous non-calcareous variegated shales have been interpreted, based on the foraminiferal, radiolarian and trace fossil assemblages from the Malinowa Shale Formation of the Grajcarek Unit (Pieniny Klippen Belt, of Poland), exposed at Trawne Stream. The deposits represent the lower part of the Uvigerinammina jankoi Zone (Turonian-?Coniacian), as based on the occurrence o f foraminifers Uvigerinammina praejankoi Neagu and U. jankoi Majzon, and radiolaria Holocryptocanium barbui Dumitrica, H. tuberculatum Dumitrica, Praeconocaryomma universa Pessagno and P. lipmanae Pessagno. Predominance of non-calcareous shales with siliceouswalled agglutinated foraminifers and radiolaria as the only biotic components, and occurrence of trace fossils typical of the Nereites facies, indicate a deep-water marine palaeoenvironment, below the CCD. Energy of bottom-waters was low, except for rare episodes o f diluted turbidite flows. Diversified foraminiferal benthic and trace fossil assemblages, abundant epi- and infaunal foraminiferal morphotypes, low values of foraminiferal dominance index, intense bioturbation of the shales, and well-developed tiering pattern of the trace fossils (including deep-tier ichnotaxa such as Zoophycos and Scolicia), indicate that the sediments were poor in organic matter and were deposited in highly oxygenated conditions. Changes in the sediment colouration (red and grey-green) are reflected in small changes within the foraminiferal benthos and trace fossil assemblages.
BAK, M. 2000. Radiolaria from the upper Cenomanianlower Turonian deposits of the Silesian Unit (Polish Flysch Carpathians). Geologica Carpathica, 51 (5) : 309-324. ABSTRACT: Upper Cenomanian to lower Turonian deposits of the Silesian Unit of the Polish Flysch Carpathians comprise a characteristic interval of green and black shales with manganese concrections, tuff and bentonites. These strata are not only distinctive lithologically, but also contain a rich radiolarian fauna. Thirty-five species of Radiolaria have been identified. Spherical cryptothoracic and cryptocephalic Nassellaria dominate in the assemblage, especially species such as Holocryptocanium barbui, H. tuberculatum, Hemicryptocapsa prepolyhedra and H. polyhedra. The systematic description of fifteen species belonging to order Spumellaria and twenty species of Nassellaria is presented herein.
BARBER, A.J., 2000. The origin of the Woyla Terranes i n Sumatra and the late Mesozoic evolution of the Sundaland margin. Journal of Asian-Earth Sciences. 18(6): 713-738
BAK, K., AND OSZCZYPKO, N. 2000. Late Albian and Cenomanian redeposited foraminifera from Late CretaceousPaleocene deposits of the Raca Subunit (Magura Nappe, Polish Western Carpathians) and their paleogeographical significance, Geologica Carpathica, 51 (6), 371-382.
ABSTRACT: The Jurassic-Cretaceous Woyla Group of northern Sumatra includes fragments of volcanic arcs and an imbricated oceanic assemblage. The arc rocks are intruded by a granitic batholith and are separated from the original continental margin o f Sundaland by the oceanic assemblage. Rocks of the arc assemblage are considered to be underlain by a continental basement because of the occurrence of the intrusive granite and of tin anomalies identified in stream sediments. Quartzose sediments associated with the granite have been correlated with units in the Palaeozoic
ABSTRACT: Late Albian abundant and diversified foraminifers and calcified radiolaria representing the Planomalina buxtorfi-Rotalipora appenninica Zone, and single Cenomanian planktonic foraminifers have been found as redeposited assemblages within lower-middle
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basement of Sumatra. From these relationships a model has been proposed in which a continental sliver was separated from the margin of Sundaland in the Late Jurassic to Early Cretaceous in an extensional strike-slip faulting regime, producing a short-lived marginal basin. The separated continental fragments have been designated the Sikuleh and Natal microcontinents. In the midCretaceous the extensional regime was succeeded by compression, crushing the continental fragments back against the Sundaland margin, with the destruction of the marginal basin, now represented only by the imbricated oceanic assemblage. Modifications of this scenario are required by subsequent studies. Age-dating of the volcanic assemblage and intrusive granites in the Natal area showed that they formed part of an Eocene-Oligocene volcanic arc and are not relevant to the model. Thick-bedded radiolarian chert and palaeontological studies in the oceanic Woyla Group rocks of the Natal and Padang areas showed that they formed part of a more extensive and long-lived ocean basin which lasted from at least Triassic until mid-Cretaceous. This raised the possibility that the Sikuleh microcontinent might be allochthonous to Sumatra and encouraged plate tectonic reconstructions in which the Sikuleh microcontinent originated on the northern margin of Gondwanaland and migrated northwards across Tethys before colliding with Sundaland. Since these models were proposed, the whole of Sumatra has been mapped and units correlated with the Woyla Group have been recognised throughout western Sumatra. These units are reviewed and the validity of their correlation with the Woyla Group of northern Sumatra is assessed. From this review a revised synthesis for the Late Mesozoic tectonic evolution of the southwestern margin of Sundaland is proposed.
reworked sediments including platform and continental basement fragments. The earliest ophiolites also show geochemical affinities with synrift and transitional mid-oceanic-ridge basalts. The oldest radiolarites on oceanic crust are so far dated as Bathonian (UAZ 6 ) and are located in the Gets nappe (western Alps), in the Balagne nappe (Corsica), and in the central Atlantic (Deep Sea Drilling Project [DSDP]; Site 534A). The oldest remnants of Alpine Tethyan crust have been identified in weakly metamorphosed cover nappes that occupy an external tectonic position in the Alpine orogenic belts, as compared to the main ophiolitic sutures. Thus, the older relics of oceanic lithosphere were the first to be accreted and transported onto the foreland during the collision. Siliceous sedimentation during the early Bajocian is correlated with westward deep-water circulation in the Alpine Tethys related to the opening o f deep seaways between Laurasia and Gondwana. In the central Atlantic no radiolarites, but thin radiolarian-rich layers, were deposited during the earliest Bathonian (UAZ 6). The similarity between radiolarian faunal assemblages and ages in the Northern Alps, Gets nappe, Betic Cordillera, and Site 534 (DSDP Leg 7 6 ) suggest a Middle Jurassic connection between the Alpine Tethys and central Atlantic. Biochronologic and isotopic ages currently indicate that oceanic spreading of the Alpine Tethys began during the Bajocian and continued until the Kimmeridgian.
BLAKE, M.C., JR. AND WENTWORTH, C.M., 2000. Structure and metamorphism of the Franciscan Complex, Mt. Hamilton area, Northern California. In: W.G. Ernst and G. Coleman Robert (Editors), Tectonic studies of Asia and the Pacific Rim. Bellwether Publishing for the Geological Society of America. Columbia, MD, United States. 2000. International Book Series. 3; Pages 295-302
BAUD, A., BECHENNEC, F., CORDEY, F., KRYSTYN, L., LE METOUR, J., MARCOUX, J., AND MAURY, R., 2001: Permo- Triassic Deposits: from Slope to Basin and Seamounts, International conference on the geology o f Oman, Muscat, January 2001, pre-conference excursion No. A01, 57 p.
ABSTRACT: Truncation of metamorphic isograds and fold axes within coherent terranes of Franciscan metagraywacke by intervening zones of melange indicate that the melange is tectonic and formed after the subduction-related metamorphism and folding. These relations are expressed in two terranes of blueschist-facies rocks of the Franciscan Complex in the Mt. Hamilton area, northern California-the Jurassic Yolla Bolly terrane and the structurally underlying Cretaceous Burnt Hills terrane. Local preservation in both terranes of basal radiolarian chert and oceanic basalt beneath continent-derived metagraywacke and argillite demonstrates thrust repetition within the coherent terranes, although these relations are scarce near Mt. Hamilton. The metagraywackes range from albitepumpellyite blueschists to those containing well-crystallized jadeitic pyroxene, and a jadeite-in isograd can be defined in parts o f the area. Primary bedding defines locally coherent structural orientations and folds within the metagraywacke units. These units are crosscut by thin zones of tectonic melange containing blocks o f high-grade blueschist, serpentinite, and other exotic rocks, and a broader, but otherwise identical melange zone marks the discordant boundary between the two terranes.
BAUD, A., BECHENNEC, F., CORDEY, F., AND MARCOUX, J., 2001: Permo-Triassic Deposits: from Shallow Water to Base of Slope, International conference o n the geology of Oman, Muscat, January 2001, postconference excursion No. B01, 40 p. BAUD, A., CORDEY, F., KRYSTYN, L., MARCOUX, J. AND RICHOZ S, 2001: The Permian-Triassic boundary in Oman, a review; International conference on the geology of Oman, Muscat, January 2001, Abstract volume, p. 21. BECHENNEC, F., GORICAN, S., ROBIN, C., CORDEY, F., AND MARCOUX, J., 2001: Al Aridh Group: revised stratigraphy and significance of a Mesozoic Hawasina unit in the Oman mountains; International conference on the geology of Oman, Muscat, January 2001, Abstract volume, p. 22.
BOUCHET Ph., DE WEVER P. & TILLIER S 2000. Les inventaires taxonomiques . In : Systématique. Ordonner la diversité du Vivant, chap. 3.: Bilans de la systématique actuelle. Rapports sur la science et la technologie n° 11, Acad. Sciences, Tec. & Doc ed., pp. 49-62.
BILL, M., O, D.L., GUEX, J., BAUMGARTNER, P.O. AND MASSON, H., 2001. Radiolarite ages in AlpineMediterranean ophiolites; constraints on the oceanic spreading and the Tethys-Atlantic connection. Geological Society of America Bulletin, 113(1): 129-143.
BRAGIN N. YU. 2000. Triassic Radiolarian Zonation in the Far East of Russia. Stratigraphy and Geological Correlation 8: 579-592. ABSTRACT: In siliceous deposits of eastern Russia we can recognize, by means of radiolarians, the following biostratigraphic units: Pseudostylosphaera fragilis Beds (upper Olenekian) and zones of Hosmadia gifuensis (lower Anisian), Triassocampe diordinis (middle Anisian), Triassocampe deweveri (upper Anisian), Triassocampe scalaris (uppermost Anisian–lowermost Ladinian), Oertlispongus inaequispinosus (the lower part of the lower Ladinian), Falcispongus falciformis (the upper part of the lower Ladinian–lower part of the upper Ladin ian), Muelleritortis cochleata (the middle–upper part of the upper Ladinian), Tritortis kretaensis kretaensis (lower Carnian), Capnuchosphaera theloides (upper Carnian), Capnodoce crystallina (lower–middle Norian), Lysemelas olbia (the lower part of the upper Norian), Betraccium deweveri (the upper part of the upper Norian), Livarella densipora (lower Rhaetian), and Globolaxtorum tozeri (upper Rhaetian). All zones distinguished in sections of siliceous monofacies are well correlative to those in carbonate and terrigenous sections far away. The detailed and persistent radiolarian biozonation of the
ABSTRACT: The history of continental breakup and oceanic spreading of the Alpine Tethys is defined by a revision of isotopic and biochronologic ages of 65 stratigraphic sections located in the Alps, Apennines, Betic Cordillera, Rif, and central Atlantic and a reinterpretation of the stratigraphic sequences of surpraophiolitic radiolarites. The biochronology of radiolarites is revised by using the deterministic approach known as the unitary association method. During the early Bajocian (unitary association zone, UAZ 3 ) radiolarite sedimentation began at the continental margin. Biochronologic ages determined in the lowermost radiolarites in basinal sequences of Tethyan margins are synchronous and mark a regional change in sedimentation regime in the Alpine Tethys. The onset of oceanic spreading of the Alpine Tethys is dated by isotopic methods as Bajocian, and is consistent with the timing of the structural evolution of the continental margins. The earliest fragments of Tethyan oceanic crust are characterized by the associations of ophiolites with deep-sea sediments, and coarse
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Middle–Upper Triassic suggest a possibility to use this paleontological group not only for concrete stratigraphic purposes (e.g., for dating siliceous sequences), but also in a wider aspects o f the global and regional Triassic stratigraphy.
Academie de Sciences Serie IIa: Sciences de la Terre et des Planetes 331 (6) : 413-418. ABSTRACT: Using radiolarian and conodont remains, a Tournaisian age has been obtained from the Lydian rocks (or lydites) of the Parnis Mount (Greece); this result is the first direct age dating o f the Lydian rocks of continental Greece. In the same area, some limestone strata, interbedded in sandstones, yield Carboniferous and Permian foraminifers; the established stratigraphy is not consistent and so, the Lydian rocks have to be considered as blocks in an olistostrome unconformably overlain or thrusted by Triassic limestones. Otherwise, the Lydian rocks are interpreted as biogenic siliceous deposits due to the absence of carbonate sedimentation (not as a high siliceous production
BRAGIN N. YU. AND EGOROV A. YU. 2000. Middle Late Triassic Radiolarians from the Dzhugadzhak Section (the Omolon Massif). Stratigraphy and Geological Correlation 8 : 362-371. ABSTRACT: Radiolarians were found in the upper Anisian, upper Ladinian, and lower Carnian deposits of the Omolon massif. Their assemblages are less diverse than the coeval Mediterranean assemblages but very similar to the Middle Triassic assemblages o f New Zealand. The identified cosmopolitan species of the assemblages enable correlation between Triassic deposits in the high and low latitudes.
CECCA, F., SAVARY, B., BARTOLINI, A., REMANE, J . , AND CORDEY. F., 2001: the Middle Jurassic-Early Cretaceous Ammonitico rosso succession at Monte Inici (Trapanese domain): sedimentology, biostratigraphy and isotope stratigraphy; Bulletin de la Société Géologique de France, in press. å
BRAGIN, N.Y., BRAGINA, L.G. AND KRYLOV, K.A., 2000. Albian-Cenomanian deposits of the Mamonia Complex, southwestern Cyprus. In: I. Panayides, C. Xenophontos and J. Malpas (Editors), Proceedings of the Third international conference on the Geology of the eastern Mediterranean. Ministry of Agriculture, Natural Resources and Environment, Geological Survey Department. Nicosia, Cyprus. 2000. Pages 309-315.
CHUTAKOSITKANON, V., CHARUSIRI, P., AND SASHIDA, K 2000. Lithostratigraphy of Permian marine sequences, Khao Pun area, central Thailand: Paleoenvironments and tectonic history. The Island Arc 9 (2) : 173-187.
ABSTRACT: The uppermost deposits of the Mamonia Complex in the Xeros Potamos area are represented by clays with intercalations of spongolites. They contain beds of radiolarian chert with AlbianCenomanian Radiolaria and blocks of Upper Triassic limestones. The presence of Triassic olistoliths may reflect the beginning of the tectonic accretion of the Mamonia Complex of the latest phase o f rifting.
ABSTRACT: Geologic mapping and subsurface lithostratigraphic investigations Tt ere carried out in the Khao Pun area (4 km 2), central Thailand. More than 250 hand specimens, 70 rock slabs, and 70 thin sections were studied in conjunction with geochemical data in order to elucidate paleoenvironments and tectonic setting o f the Permian marine sedimental uv sequences. This sedimentary succession (2485 m thick) was re-accessed and re-grouped into three lithostratigraphic units, namely in ascending order the Phu Phe, Khao Sung and Khao Pun Formations. The Lower to lower Upper Permian sedimentary facies indicated the transgressive/regressive succession of shelf sea/platform environment to pelagic or abyssal environment below the carbonate compensation depth. The sedimentological and paleontological aspects, together with petrochemical and lithological points of view reveal that the oldest unit might indicate an Early Permian shelter ed shallow or lagoonal environment. Then the depositional basin became deeper as suggested by the prolonged occurrence of bedded chert-limestone intercalation with the local exposure of shallower carbonate buildup. Following this, the depositional environment changed to pelagic deposition, as indicated by laminated radiolarian (e.g. Follicucullus sp.) cherts. This cryptic evidence might indicate the abyssal environment during middle Middle to early Late Permian; whereas, previous studies advocated shelf-facies environments. Following this, the depositional condition might be a major regression on the microcontinent close to Indochina, from the minor transgressive/regressive cycles that developed within a skeletal barrier; and, through the lagoon with limited circulational and anaerobic conditions, on to the tidal fiat to the sheltered lagoon without effective land-derived sediments.
BURMESTER, R.F., BLAKE, M.C., JR. AND ENGEBRETSON, D.C., 2000. Remagnetization during Cretaceous normal superchron in eastern San Juan Islands, WA; implications for tectonic history. In: B. Housen, F. Heller and C. Mpodozis (Editors), Advances i n paleomagnetism and tectonics of active margins; in honor of retirement of Myrl E. Beck, Jr. Tectonophysics. 326: 7392. ABSTRACT: The Eastern San Juan Islands expose an island arc ophiolite sequence and one or more ocean floor terranes. Cover rocks of the former, including red radiolarian tuff and arc-derived sandstone, have no penetrative fabric and lack high-pressure minerals. In contrast, pillow basalts and ribbon cherts of the latter are strongly deformed and the overlying metagraywacke is folded with a penetrative axial plane cleavage. All ocean floor rocks have aragonite in veins, indicative of higher-pressure conditions than experienced by the island arc rocks. A downward magnetization i s common to the ocean floor rocks, consistent with widespread remagnetization during the Cretaceous normal superchron. This magnetization is carried by magnetite and, in red rocks, by hematite; fluid flow during or after deformation and high P metamorphism likely facilitated remagnetization at low temperature. The magnetic directions are somewhat scattered but most are moderately to steeply down to the southeast. They are f a r from directions expected with or without northward transport o f Baja BC. Rotation of observed directions into agreement with those expected for either present or more southerly locations also rotate structural elements in the host rocks. Three alternative rotation histories explored here all produce structural reconstructions that differ considerably from the present structure. A tectonic history o f the eastern San Juan Islands based on any of these reconstructions would be superior to one based on present attitudes of structures. This is because at least a constraint that the restored paleomagnetic directions match a paleomagnetic field direction i s satisfied. Choices among alternative reconstructions would become clearer with better understanding of relative ages of specific structures and their magnetizations. Improved geologic understanding of the regional setting where the rocks could have been deformed and remagnetized would also help.
CORDEY, F., BAUD, A., BECHENNEC, F., GORICAN, S., KRYSTYN, L., MARCOUX, J., ROBIN, C., AND RICHOZ, S., 2001: Permian-Triassic deep water sediments of the Wadi Wasit revisited; International conference on the geology o f Oman, Muscat, January 2001, Abstract volume, p. 29. CRAIG, H., SOMAYAJULU, B.L.K. AND TUREKIAN, K.K., 2000. Paradox lost: Silicon 32 and the global ocean silica cycle. Earth and Planetary Science Letters, 175(3-4): 297308. ABSTRACT: The 32Si Paradox is that the GEOSECS measurements o f Si specific activity in silica collected on ferric hydroxide-coated fibers are essentially uniform throughout the deep water of the global oceans [Somayajulu et al., Earth Planet. Sci. Lett. 85 ( 1 9 8 7 ) 329-342; 107 (1991) 197-216]. Peng, Maier-Reimer, and Broecker have argued that 32Si specific activities in Indian and Pacific deep water should be 3-5 times lower than in the deep Atlantic, because the dissolved SiO2 concentrations are higher than in the Atlantic by this factor, and because cosmogenic 32Si should be essentially confined to the ocean basins in which it falls due t o its short half-life relative to mixing times for water interchange between the oceans. Thus these authors proposed that the entire 32
CARIDROIT, M., FERRIERE, J., DEGARDIN, J.M., VACHARD, D., AND CLEMENT, B. 2000. First age dating of the Lydian stones in the Inner Hellenides (Mount Parnis, Greece); geological significances. Comptes Rendus de l' 22
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GEOSECS 32Si data set 'may be flawed'. The resolution of the 32Si Paradox is straightforward. Silica collected on the acrilan fibers is a two-phase mixture of biogenic particulate SiO2 (opaline tests o f diatoms and radiolaria) and silica scavenged chemically from dissolved SiO2 in ocean water. Particulate silica is the high-activity component in this mixture, and dissolved SiO2 is the low-activity end-member. Thus the mixing trajectories on 'Cornucopia plots' o f specific activity vs. reciprocal SiO2 recovered weights overlap in specific-activity range, regardless of the different concentrations and specific activities of dissolved silica in the deep waters. The specific activities of dissolved SiO2 in the Pacific, Indian, and Atlantic oceans, as deciphered from the two-component total activity data, are 0, 2.6, and 4.5 dpm/kg SiO2 The atmospheric production rate of 32Si has been calculated and is found to be 0 . 7 2 atoms/m 2s. This value is much lower than in previous calculations, which were based on the Lal and Peters plots of stratospheric fallout that incorrectly use geomagnetic latitude for scaling the fallout patterns. Correcting these curves to scale by geographic latitude, which controls the stratospheric 'dumping' pattern, we show that the 32Si concentrations in Indian rains represent the total fallout from both stratosphere and troposphere, rather than only tropospheric fallout as was previously assumed. The new value o f the atmospheric production rate is consistent with the low activities of the dissolved silica in the three oceans, which are modulated t o some extent by radioactive decay of 32Si during the sequestering o f particulate silica in sediments before regeneration in bottom waters.
as 'Gault' or 'Mesocretace'). The definition of the Joux Verte Formation is partly based on the argument that in the formerly accepted 'Serie a Quartzites', contrary to what its name suggests, detrital quartz represents only a minor part of the series, most o f the SiO2 being of diagenetic origin. The Joux Verte Formation exists only in the Chablais region and is absent in the Romandes region. I t ranges from the Late Barremian to the Middle Turonian. The lithology consists mostly of black shales with intercalations of spongial, radiolarian and foraminiferal cherts. Three major succession can be defined, each beginning with thin laminated black shales followed by relatively thick cherty limestones. Areal extension and facies variability suggest an ESE-WNW oriented basin with locally differential subsidence. The black shale levels can be correlated within the basin and compared to coeval world-wide oceanic anoxic events.
DANELIAN T. & ALEXANDER I. 2000. Stable oxygen isotope analysis of Pliocene marine diatomite-marl cyclic sedimentation in the Heraklion District (Crete, Greece) Geological Society of Greece, Special Publication, 9: 53-61. ABSTRACT: Several Pliocene finely laminated diatomites o f significant thickness occur in the various Neogene sub-basins, south of Heraklion city. They are intercalated by marls which usually contain abundant bivalves and evidence of burrowing. We have been mainly concerned with the origin of two diatomite-marl cycles in relation to the stable oxygen isotope record. In general, analyses o f the planktonic species Globigerina bulloides and the benthic Cibicidoides spp. show coupled variation in d18O value, which correlate well with observed lithologic variations. Marl horizons are typically characterized by more positive d18O values, while conversely, diatomites by relatively depleted d18O values. Our results underline the importance of surface water runoff (i.e. lower salinity variations) as a primary mechanism controlling diatomite formation.
CUI, Z., HUA, H. AND SONG, Q., 2000. The Late Ordovician radiolarian assemblage of the North Qinling back-arc basin, China. Acta Geologica Sinica, 74(3): 254-258. ABSTRACT: The Weibei area is located on the north side of the Weihe River near the Qinling Mountains. During the early Palaeozoic it belonged to the North China carbonate platform, but at the beginning of the Late Ordovician, it subsided and developed into a deep-water basin merging into the North Qinling back-arc basin, where it received carbonate slope deposits of a total thickness o f about 800 m, including thin-bedded limestones, cherts, tuff and brecciform limestone as well as slumped limestones. This set o f strata, named the Zhaolaoyu Formation by Mei Zhichao et al., yields radiolarians, graptolites and conodonts in its lower part. Graptolites and conodonts collected from the thin-bedded limestones indicate a Caradocian age. The well-preserved radiolarian Inanibigutta aff. inconstans- Syntagentactinia biocculosa assemblage produced in i t is characterized by a high diversity with 7 families, 14 genera and 23 species, the dominance of Inaniguttidae, Halpentactiniidae and Polyentactiniinae, and especially Inanigutta, Inanibigutta, and Polyentactinia, inadequacy of Entactiniinae and Palaeoscenidiidae existing dominantly in the Ordovician of Europe, America and Australia, in particular, and absence of the important element, Kalimnasphaera, of Australia and America. Therefore, the general feature of this assemblage is very similar to that of the LandeiloCaradocian assemblage of Kazakhstan. As is known at present, Asia is the place rich in the most highly diverse Ordovician radiolarian fossils. These facts indicate that the ancient Qinling Ocean can have been related to the Palaeasia Ocean.
DANELIAN T. & FLOYD J. (in press) - Progress i n describing Ordovician siliceous biodiversity from the Southern Uplands (Scotland, U.K.)- Transactions of the Royal Society of Edinburgh, Earth Sciences. ABSTRACT: Leaching of Ordovician cherts from the Southern Uplands using dilute HF has yielded numerous radiolaria, sponge spicules and a few conodonts. Although many of the radiolaria have suffered intense recrystallisation, it nevertheless proved possible to extract for SEM examination some examples with exquisitely preserved micro-structure. Despite this, the radiolaria have not proved sufficient, on their own, to answer the outstanding biostratigraphical question of one continuous or two separate episodes (Arenig and Llanvirn/Caradoc) of chert sedimentation in the Southern Uplands. This is partly because the biostratigraphy o f Lower Palaeozoic radiolaria is still quite poorly known. A new radiolarian species, Protoceratoiciskum clarksoni Danelian, has been identified and described from cherts in the Crawford area. In addition, the distinctive sponge species Konyrium varium Nazarov & Popov, has also been found for the first time in Southern Uplands cherts. This new occurrence, in deep water sediments, suggests a much wider habitat for this unusual sponge. Amongst the few conodont elements extracted, one can be identified as probably belonging to the genus Periodon.
DALL, A.S., 2000. The Cretaceous of the Breccia nappe (French and Swiss Prealps). New data and an attempt towards a stratigraphic and palaeogeographic synthesis. Comptes Rendus de l' Academie de Sciences Serie IIa: Sciences de la Terre et des Planetes, 330(9): 639-644
DANELIAN T. & JOHNSON K.G. (in press). Patterns of biotic change in Middle Jurassic to Early Cretaceous Tethyan Radiolaria - Marine Micropaleontology.
ABSTRACT: Two new formations are defined in the lower and middle Cretaceous sediments of the Breccia nappe within the Swiss and French Prealps, the Bonave Formation and the Joux Verte Formation. The Bonave Formation replaces the historical and informal 'Calcaires a Silexites' which were considered to constitute a member within the Upper Breccia Formation. The definition of the Bonave Formation is based on the argument that sufficient lithologic change exists within the Upper Breccia Formation to warrant the definition of a new formation. According to calpionellids, the Bonave Formation ranges from the Late Tithonian to the Barremian and comprises a fine-grained lower part with abundant nodular chert and a detrital upper part with less abundant chert dominated by calciturbidite deposits topped by breccias. The Bonave Formation exists in its entirety only in the Chablais region; in the Romandes region only small remnants may be found. The study of the spatial extension and facies variations in the Chablais region suggests a ESE-WNW oriented basin which was fed from the north-west. The Joux Verte Formation replaces the 'Serie a Quartzites' (also known
ABSTRACT: The rate of taxic turnover of nearly 400 radiolarian species/subspecies is analyzed in order to document long term biotic change of plankton during the Middle Jurassic to Early Cretaceous (Aalenian to Aptian). The pattern and dynamic o f diversity change is described using four indices: rate of species first and last occurrence, rate of diversification and rate o f turnover. Plots of cumulative sampling effort suggest that the analysed data represent an adequate sample of total standing diversity for most examined stages. Rates of species f i r s t occurrence exceed rates of last occurrence for most of the Middle Jurassic, except for the middle Bajocian. In contrast, the Late Jurassic was a time of decreasing radiolarian diversity and the Kimmeridgian records the lowest rate of diversification. It i s followed by a dramatic increase in first occurrences near the Jurassic-Cretaceous boundary with as a result the highest rate o f diversification recorded in the late Tithonian. Regional radiolarian diversity was stable throughout most of the Early Cretaceous. A
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stratigraphic permutation test was performed to assess the influence of uneven sampling on the observed pattern of taxic turnover and identified the intervals for which randomly obtained patterns are significantly different from the observed pattern. The Kimmeridgian and late Tithonian events coincide with substantial climate-derived perturbations in water cycling, nutrient supply and oceanic productivity. They point to a negative relationship between radiolarian macroevolution and changes in the state of nutrient availability, although further work is needed to refine the temporal resolution of this relationship and to explore ecological aspects o f its causal link with respect to radiolarian evolution.
age and the overlying siliceous shales Late Jurassic. The previously identified Calpionellid horizon at the top of Profitis Ilias siliceous marls is now regarded as early Valanginian in age. The above chronostratigraphic constraints allow tentative correlations to be made between Profitis Ilias and Pindos-Olonos sedimentary units. Finally, the palaeoceanographic significance of the studied series in Rhodes and potentially similar pelagic sequences in the Marmaris area of Turkey are discussed.
DENG, X. AND UNDERWOOD, M.B., 2001. Abundance of smectite and the location of a plate-boundary fault, Barbados accretionary prism. Geological Society of America Bulletin, 113(4): 495-507.
DANELIAN T. & ROBERTSON A.F.R. 2001. Neotethyan evolution of eastern Greece (Pagondas Mélange, Evia island) inferred from Radiolarian biostratigraphy and the geochemistry of associated extrusive rocks - Geological Magazine 138: 345-363.
ABSTRACT: Isolating the respective roles of factors responsible for the initiation and localization of fault zones remains one of the more important goals of research in neotectonics. The frontal decollement zone of the northern Barbados accretionary prism provides several important clues as to how the interwoven variables of clay mineralogy, fluid flow, chemical interactions, and sediment physical properties affect strain localization. This plate-boundary fault is centered at a lithologic contact between Miocene claystone and fine-grained Oligocene turbidites. The fault zone is nearly 40 m thick (at Ocean Drilling Program Site 948), and its upper part passes through smectite-rich deposits. A sharp minimum in percent smectite and a maximum in percent illite mark the base of the decollement. There is a consistent increase in percent smectite with distance above the base of the decollement, but the top of the decollement is poorly defined by clay mineralogy. The intrinsic mechanical weakness of strata with abundant smectite-group clays probably influences where the fault tip propagates into the undeformed stratigraphy of the Atlantic abyssal plain. A second inherited parameter is the local abundance of radiolarians, which contribute to higher than normal porosities. Sediment shear strength also decreases because pore pressure within the fault zone is significantly greater than hydrostatic. The principal cause o f excess pore pressure seems to be updip fluid advection; in theory, however, decreases in pore-fluid salinity and porosity collapse should increase the amount of physicochemical stress generated by expandable clay minerals. The imported fluid is unusually low in salinity because it has migrated from zones of deeper seated dehydration reactions. If fresher pore water migrates to the propagating tip of the decollement, its arrival should increase smectite swelling and reduce the shear strength of the mudstone even more. The location and evolution of the decollement, therefore, are controlled by a complicated interplay of static factors inherited from the abyssal Atlantic stratigraphy and dynamic factors associated with episodic fluid flow and changing fluid chemistry.
ABSTRACT: This paper presents new radiolarian biostratigraphic and igneous/metamorphic geochemical data for a Mesozoic volcanic-sedimentary mélange on the island of Evia (Euboea or Evvoia), eastern Greece. This mélange includes dismembered thrust sheets and blocks of radiolarian chert and basalt. Biostratigraphic age data show that radiolarites interbedded with basalt-derived, coarse clastic sediments near the base of a coherent succession were deposited in Middle and Late Triassic time (Late LadinianCarnian, Norian ?). Geochemical evidence shows that associated extrusives, of inferred Triassic age, range from "enriched" alkaline basalts, to "transitional" basalts, and more "depleted" MOR-type basalts. Amphibolite facies meta-basalts from the metamorphic sole of the over-riding Evia ophiolite exhibit a similar chemical compositions. Both the basalts and the meta-basalts commonly show an apparent subduction-related influence (e.g. relative Nb depletion) that may have been inherited from a previous subduction event in the region. The basalts are interpreted to have erupted during Middle-Late Triassic time (Late Ladinian-Carnian), related t o initial opening of a Neotethyan ocean basin adjacent to a rifted continental margin. Radiolarites located stratigraphically higher in the coherent succession studied are dated as Middle Jurassic (Late Bathonian-Early Callovian). Similar-aged radiolarites are depositionally associated with ophiolitic rocks (including boninites), in some other areas of Greece and Albania. During initial ocean basin closure (Bajocian-Bathonian) the adjacent shallow-water carbonate platform (Pelagonian zone) disintegrated to form basins in which siliceous sediments were deposited and highs on which shallow-water carbonates continued to accumulate. This facies differentiation is seen as a response to crustal flexure as the Neotethyan ocean began to close. The over-riding Pagondas Mélange and other similar units in the region are interpreted as accretionary prisms related to subduction of Neotethyan oceanic crust in MiddleLate Jurassic time. These mélanges were emplaced, probably diachronously during Oxfordian-Kimmeridgian time, when the passive margin collapsed, creating a foredeep ahead of advancing thrust sheets of mélange and ophiolites.
DESCHAMPS, A., MONIE, P., LALLEMAND, S., HSU, S.K. AND YEH, K.Y., 2000. Evidence for Early Cretaceous oceanic crust trapped in the Philippine Sea Plate. Earth and Planetary Science Letters, 179(3-4): 503-516. ABSTRACT: The Huatung Basin is a small oceanic basin located east of Taiwan. Previous age estimates from magnetic lineation studies indicated an Eocene age for the basin, and formation from the Central Basin Spreading Center of the West Philippine Basin during the last phase of spreading in Middle Eocene. New Ar/Ar ages obtained on gabbros dredged on oceanic basement highs of the Huatung Basin are Early Cretaceous. These old ages are consistent with Early Cretaceous ages determined on radiolarian assemblages from Lanyu Island (Luzon Arc). We have performed magnetic anomalies modeling for an Early Cretaceous oceanic crust. Our results are in good agreement with new Ar/Ar ages determinations. The best fit is indeed obtained with an opening of the Huatung Basin during the Early Cretaceous from 131 to 119 Ma, with a half spreading rate varying between 25 and 30 mm/yr. The spreading center appears to be located south of the actual basin. The abnormal depth (5500 m instead of 5900 m) and thickness ( 1 2 km instead of 6 km) of the crust beneath the basin indicate that there was probably an excess supply of magma during its formation. We propose that the basin is a fragment of the former 'proto-south China Sea' or possibly the 'New Guinea Basin' that has been trapped by the Philippine Sea Plate. (C) 2000 Elsevier Science B.V. All rights reserved.
DANELIAN, T., LEKKAS, S. AND ALEXOPOULOS, A., 2000. Discovery of Triassic radiolarites in an ophiolitic complex of the southernmost Peloponnese (Agelona, Lakonia, Greece). Comptes Rendus de l' Academie de Sciences Serie IIa: Sciences de la Terre et des Planetes, 330(9): 639 644. ABSTRACT: A relatively small ophiolitic complex in the southern Peloponnese (Agelona) is composed mainly of serpentinites, amphibolites and gabbros. Diagnostic Carnian-Norian radiolaria were extracted from a few metres of red-brownish radiolarian cherts overlying gabbros. The contact between radiolarites and gabbros seems to be stratigraphic. These Late Triassic deep-sea sediments would represent accumulation of radiolarian ooze on a rugged Tethyan oceanic floor situated near a medio-oceanic ridge.
DANELIAN T., BONNEAU M., CADET J.P., POISSON A. & VRIELYNCK B. (in press). Palaeogeographic and palaeoceanographic implications of new and revised biochronostratigraphic constraints from the Profitis Ilias unit (Rhodes, Greece) - Bulletin of the Geological Society o f Greece.
DE WEVER P. 2000. Le temps des crises. In JP Lubliner: Tour Eiffel, le voyage immobile, edit. Le Collectionneur, p.67.
ABSTRACT: Middle Oxfordian-early Kimmeridgian radiolaria, extracted from the top of radiolarites of Profitis Ilias unit (Rhodes island), suggest that the latter are essentially Middle Jurassic in
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Bibliography - 2000-2001 ABSTRACT: A new radiolarian order - Archaeospicularia - i s proposed for some Lower Paleozoic radiolarians previously considered to belong to Spumellaria and to Collodaria. It i s characterized by a globular shell made of several spicules which can be free, interlocked, or fused to formed a latticed wall. The present paper gives the definition of this order and proposes a f i r s t classification. It is supposed that the Archaeospicularia represents the oldest radiolarian group and that in the Lower Paleozoic it gave rise to the orders Entactinaria, Albaillellaria, and probably Spumellaria by the reduction of the number of initial spicules. The origin of this order and its relationships with other groups o f organisms with siliceous skeletons are also briefly discussed
DE WEVER P. 2000. Europa im Mesozoikum. In. Europâische Fossillagertätten (G. Pinna coord.). E.P.A., Springer, Berlin-Heidelberg, pp.65-71. DE WEVER P. 2000. Stratigraphic and paleobiogeographic results. Peritethys meeting, CNRS, Paris 23-24 nov.2000; Abstract, p. 10. DE WEVER P. 2000. La systématique et les crises. In: Systématique. Ordonner la diversité du Vivant, chap. 4.: La recherche en systématique. Rapports sur la science et la technologie n° 1, Acad. Sciences, Tec. & Doc ed., pp. 108112.
FANG, A., LI, J., HOU, Q., LI, H. AND HAO, J., 2000. The assemblages of the radiolaria fossils found in 'Yisak group' of West Kunlun of Xinjiang, and discussion on its age. Scientia Geologica Sinica, 35(2): 212-218.
DE WEVER P., CORNEE A. 2000. La notion de stratotype. In Frohlich F. & Schubnel (comm.): Le Lutetien la pierre de Paris. MNHN éditeur, Paris, pp.6-13.
ABSTRACT: The Yisak group is a newly built stratagraphical unit which was found in 1980's. Its outcrop lies in the 5th suture zone of Qinghai - Tibet plateau. It is also the chief component of the Kuda ophiolitic suite. From the geological profile of Yixikegou, the Yisak group is composed of three lithological parts: the lower part of basic lava, pillow lava and altered gabbro; the middle part of andesites and pyroclastic rocks; and the upper one of a set of deep - marine sediments with apparent turbidite characteristics. Since no definite evidence of bio-fossils has ever been found in this group, it is very difficult to determine its age properly. However, the age of this group is judged as Late Proterozoic Era according to isotopic data o f its related igneous rocks by former researchers. The authors have made a thorough study upon the geological section of Yixikegou, and found two assemblages of radiolaria fossils in the upper part of the Yisak group. By comparison with the radiolaria fossils found in other places of the world, they are assigned to two geological age: the Early Paleozoic and the Late Devonian to Early Carboniferous, respectively. Although the first radiolaria fossil assemblage occurs only about 150m lower than the second one in the profile section o f Yixikegou, they are seperated by a thrust fault. Therefore, this turbidite set should at least be divided into two stratigraphical slices in varied geological times. Combined with the studies upon the age of the lower part of the Yisak group, we do not think i t suitable for the Yisak group to be considered as one single stratigraphic units. It should be at least divided into two stratigraphic units: the Early Paleozoic one which include the lower and middle parts of the formly 'Yisak group', as well as the lower part of the turbidite set, and the D 3 – C 1 one which constitutes o f the upper part of the turbidite set in Yixikegou section.
DE WEVER P., BOURDILLON C. & VILLAIN J.-M. 2000. Intérêt industriel de la micropaléontologie. . In: Systématique. Ordonner la diversité du Vivant, chap. 5 : Systématique et questions de Société. Rapports sur la science et la technologie n° 1, Acad. Sciences, Tec. & Doc ed., pp. 162-166. DE WEVER P., DAVID B., RAVENNE Ch., BROUTIN J. 1 & GUIRAUD M. 2000. Relations géosphère-biosphère. In: Systématique. Ordonner la diversité du Vivant, chap. 4.: La recherche en systématique. Rapports sur la science et la technologie n° 1, Acad. Sciences, Tec. & Doc ed., pp. 113128. DE WEVER P., DUMITRICA P., CAULET J.P., NIGRINI C. & CARIDROIT M., 2001. Radiolarians in the sedimentary record. Gordon & Breach Science publ., London, 524 pages. DOLVEN, J.K. AND BJØRKLUND, K.R., 2001. An early Holocene peak occurrence and recent distribution of Rhizoplegma boreale (Radiolaria): A biomarker in the Norwegian Sea. Marine Micropaleontology, 42/1-2: 25-44 ABSTRACT: Several sediment cores in the Norwegian Sea reveal, in the early Preboreal, abundance peaks of up to 14% of Rhizoplegma boreale (Cleve). These peaks generally coincide with a transition from cold to warm water radiolarian assemblages and a high number of diatom valves (Chaetoceros sp.), indicating highly productive surface waters. The R. boreale peak represents an ecological event caused by an influx of North Atlantic Water, and can potentially be used as a chrono-stratigraphic marker within the eastern part of the Norwegian Sea. In core HM 79-6.2 the R. boreale peak reaches 9 . 2 %, and is found between two 14C-dated ash layers. We estimated the age of the R. boreale peak to be 9,880 ± 55 yrs. B.P. by linear interpolation between datum points. The characteristic stratigraphical distribution of R. boreale was used to establish a better age model for the studied section. R. boreale has been mapped in surface sediment samples from the Iceland Sea, the Norwegian Sea and the Norwegian fjords. An oceanic form with six and a neritic form with eight radial spines were found in these areas. Recent distribution of R. boreale is mainly confined to the Nordic Seas (Greenland, Iceland, and Norwegian Seas), the North Pacific (including the Bering Sea and Sea of Okhotsk) and in the Southern ocean. The highest occurrence of R. boreale is found in areas with high primary production and mixing of water masses.
FARINACCI, A., FIORENTINO, A. AND RIDOLFI, V., 2000. Aspects of Jurassic radiolarite sedimentation in a ramp setting following the 'mid-Late Jurassic discontinuity', Barla Dag area, Western Taurus, Turkey. Geological Society Special-Publication. 173: 163-170. ABSTRACT: The Barla Dag area of southwestern Turkey and i t s surroundings represent one of the most characteristic Tethyan regions in which the unique characteristics of the Jurassic radiolarite deposits permit detailed study of this enigmatic facies. Hitherto, radiolarites of Western Tethys have not been studied in sufficient detail to yield the information required for unequivocal interpretation of this siliceous sedimentary event. Moreover, few o f the occurrences of Tethyan radiolarites during the Jurassic have been adequately explained by palaeoenvironmental causes deduced from facies analysis. In the Barla Dag area, the main radiolarite episode began after the 'main gap' or mid-Late Jurassic discontinuity, a 25 Ma hiatus extending from the Early Bajocian t o the Kimmeridgian. These radiolarites are interbedded with biocalcarenites characterized by shallow-water shells. They formed in a ramp environment subject to strong storm oscillatory movements and were deposited within, or just below, wave base. Pre-existing platforms were converted into ramp settings by a widespread drowning episode, mainly following postulated regional warping that led to creation of the 'main gap'. Coincident with this event, the differentiation of rimmed platform lagoonal organisms and typical ramp inhabitants, such as Tubiphytes, took place. Furthermore, nearby platforms, unaffected by the extensional faulting (e.g. the Davras Dag), were sites of carbonate accumulation receiving only a few radiolarians. On the other hand, displaced shallow-water organisms of the same age (typical of the restricted lagoons flanking the rimmed platforms such as pfenderinas, kurnubias and Clypeina jurassica) are absent from the sequences o f calcarenites interbedded with radiolarian cherts. Replacement o f
DUMITRICA, P. 1999. On the presence of central capsular membranes of Radiolaria in fossil state. Revista Espanola de Micropaleonologia, 31(2): 155-183. DUMITRICA, P., CARIDROIT, M. AND DE, WEWER, P., 2000. Archaeospicularia, new Radiolarian order; a new step for the classification of the Lower Paleozoic Radiolaria. Comptes Rendus de l' Academie de Sciences Serie IIa: Sciences de la Terre et des Planetes, 330(8): 563-569.
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deep basins by ramps is indicated by the changing depositional bathymetry of some radiolarites. It is tentatively attributed to the extension of shallow seas and narrowing of the oceanic realm between Eurasian and African Plates in Western Tethys.
ABSTRACT: Radiolarian fossil study in the sediment cores collected during the pre- and postdisturbance cruises of the Environmental Impact Assessment (EIA) Indian Ocean Experiment (INDEX) program of deep sea mining in the Central Indian Ocean Basin suggests a pronounced directional deposition of fossil radiolarians exhumed during the deep sea benthic disturbance experiment. The relative occurences of the Stylatractus universus species that became extinct ~0.425 million years before present were mostly confined to the older and deeper strata of the sediment of the disturbance tract in the southwestern direction. This pattern is remarkable and suggests that the disturbance plume has been preferentially redeposited in the southwestern direction. This observation is in concurrence with the prevailing southwestern abyssal current during the disturbance experiment in the Central Indian Basin.
FENG, Q. L., YANG, F. Q., ZHANG, Z. F., ZHANG, N. GAO, Y. Q., AND WANG, Z. P.., 2000. Radiolarian evolution during the Permian and triassic transition in South and Southwest China. In : H. Yin, J. M. Dickens, G. R. Shi and J. Tong (Editors) Permian-Triassic evolution of Tethys and Western Cirum-Pacific. Elsevier pp. 309-326. FUNAKAWA, S., 2000. Internal skeletal structures of the Cenozoic genera Gondwanaria, Lipmanella and Lithomelissa (Plagiacanthidae, Nassellaria) and their taxonomy. Micropaleontology, 46(2): 97-121.
HART, M.B., 2000. Foraminifera, sequence stratigraphy and regional correlation; an example from the uppermost Albian of Southern England. Revue de Micropaleontologie, 43(12): 27-45.
ABSTRACT: Internal skeletal structure of Nassellaria, Radiolaria forms during the early stages of ontogeny and is used as one of the main criteria of suprageneric classification. Its detailed knowledge represents also the structural basis of taxonomy of some genera. In order to use it properly a new descriptive terminology of the internal skeletal structure is developed for some large-cephalis bearing nassellarians. Eight Cenozoic to recent nassellarians assigned t o three genera, Gondwanaria, Lipmanella and Lithomelissa including four new species, are described using this new terminology. Furthermore, on the basis of initial skeletal structure, the author clarifies the suprageneric taxonomy of genera, Gondwanaria Petrushevskaya and Lipmanella Loeblich and Tappan.
ABSTRACT: While the general principles of sequence stratigraphy are well-established, the detailed distribution of fossils within sequences is less well known. Emery and Myers (1996) indicate that the most distinctive palaeontological information comes from the Maximum Flooding Surface where diverse assemblages, often dominated by planktonic taxa, are characteristic. The palaeontological features of a number of sequences in the uppermost Albian of Southern England have been documented in order to provide detailed palaeontological information on the distribution of foraminiferal taxa within the different systems tracts (Van Wagoner et al., 1988). Within the uppermost Albian in Southern England the Gault Clay Formation presents a well-known succession of marine strata containing abundant Foraminiferida and other microfossils. The ammonite stratigraphy is also well established. Using coastal and borehole sections at Folkestone, samples from cored material recovered prior to the construction o f the Channel Tunnel as well as samples from the construction phase, it has been possible to provide a detailed analysis of the uppermost Albian. This includes information on a little known cycle o f sedimentation ('Zone 6a') which is located between the uppermost Gault Clay Formation and the Glauconitic Marl (of Cenomanian age), but which is only known from the area of the Channel Tunnel. In S.W. England coeval strata contain fewer smaller Foraminiferida and other microfossil groups but do contain ammonites and large numbers of orbitolinids [large Foraminiferida]. The correlation o f this sequence across the whole of Southern England is presented. Planktonic Foraminiferida (mainly hedbergellids) show a concentration in the Transgressive Systems Tract and around the Maximum Flooding Surface with fewer individuals being recorded in the Highstand Systems Tract. Specimens of Globigerinelloides bentonensis (MORROW), although present throughout, are very much larger around the level of the Maximum Flooding Surface and are associated with a reported occurrence of keeled rotaliporids and planomalinids, together with rare specimens of radiolaria. The benthonic Foraminiferida also show variations through the various systems tracts, especially in S.W. England where specimens o f Orbitolina are commonly found associated with a major flooding event in the marginal marine sediments of the area.
GARDIN S., BULOT L., COCCIONI R., DE WEVER P., HISHIDA K. & LAMBERT E. 2000. The ValanginianHauterivian hemipelagic successions of the Vocontian Basin (SE France): New high resolution integrated biostratigraphical data. Poster. GAST, R.J., MCDONNELL, T.A. AND CARON, D.A., 2000. srDNA-Based taxonomic affinities of algal symbionts from a planktonic foraminifer and a solitary radiolarian. Journal o f Phycology, 36: 172-177. ABSTRACT: Planktonic sarcodines (acantharia, radiolaria, and planktonic foraminifera) are oceanic amoeboid protozoa that often harbor a variety of microalgae as intracellular symbionts. The identity and function of these endosymbiotic algae have intrigued and perplexed biologists for more than a century. The most conspicuous and well-studied symbiotic algae of planktonic foraminifera and radiolaria are dinoflagellates, but a variety o f nondinoflagellate taxa have also been reported. Ultrastructural features have been used to characterize some of these nondinoflagellate algae, but rarely has this led to clear taxonomic affiliations. We analyzed the nuclear small subunit ribosomal DNA (srDNA) isolated from the symbionts of the spinose planktonic foraminiferan Globigerinella siphonifera d'Orbigny ( = Globigerinella aequilateralis Brady) and a solitary radiolarian (Spongodrymus sp. Haeckel) in order to determine the identity of these symbionts. The small coccoid algae isolated from G. siphonifera correspond to the Type I symbionts described by Faber et al. (1988). Phylogenetic analysis of the srDNA sequences places these symbionts within the prymnesiophyte (haptophyte) lineage, closer to Prymnesium Conrad than to Phaeocystis Lagerheim. To our knowledge, this is the f i r s t confirmed case of a symbiotic prymnesiophyte. In addition, we were able to examine the level of sequence heterogeneity between symbionts isolated from different individuals of a single host species. The three isolates in this study had srDNA sequences that were almost identical, indicating that the three were all of the same species. Very green symbiotic algae were isolated from three solitary radiolaria identified as species of Spongodrymus. The symbiont srDNA sequences from the three individual hosts were identical to each other, again implicating a single species of algae in that symbiotic association. These symbionts are prasinophytes most closely related to the clade containing Tetaselmis convolutae Norris, Hori et Chihara. Tetraselmis convolutae is the algal symbiont of the marine flatworm, Convolutae roscoffensis Graff.
HASSANIPAK, A.A. AND GHAZI, A.M., 2000. Petrology, geochemistry and tectonic setting of the Khoy ophiolite, northwest Iran: Implications for Tethyan tectonics. Journal of Asian Earth Sciences. 2000; 18(1): 109-121 ABSTRACT: The Khoy ophiolite in northwestern Iran represents a remnant of oceanic lithosphere formed in the Mesozoic Neo-Tethys. This northwest-southeast trending ophiolite complex consists from bottom to top (east to west) of a well-defined basal metamorphic zone, peridotites (dunite, harzburgite) and serpentinized peridotite, gabbros, sheeted dikes, pillow and massive lava flows, and pelagic sedimentary rocks, including radiolarian chert. The rocks of the metamorphic zone have an inverse thermal gradient from amphibolite facies to greenschist facies. The high-grade metamorphic rocks are immediately adjacent to the peridotite and the gabbros and the low-grade rocks are in contact with the Precambrian Kahar Formation. Based on mantle-normalized incompatible trace element diagrams there are two distinct types o f basalt flows present at the Khoy ophiolite: (1) massive basalts that have patterns virtually identical to E-MORB, and (2) pillow basalts that have more primitive chemical composition whose trace element patterns plot between E-MORB and N-MORB. The chondrite-
GUPTA, S.M., 2000. Biostratigraphic analysis of the top layer of sediment cores from the reference and test sites of the INDEX area. Marine Georesources and Geotechnology, 18(3): 259-262. 26
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Bibliography - 2000-2001 ancestral Tian Shan. Temporal changes in sandstone composition are consistent with episodes of Mesozoic deformation in the Tian Shan. Each deformational episode increased physiographic relief o f the ancestral range, produced renewed downcutting and erosion o f source rocks, and resulted in the deposition of compositionally very immature sandstone in adjacent basins. Although a regional early Mesozoic megamonsoon and an Early Cretaceous rain shadow cast across the northern Tarim basin are interpreted from regional facies and paleontologic data, neither paleoclimatic phenomenon appears to have significantly modified sandstone composition in the study area. Calculations of intergranular volume (% porosity + % cement) indicate that porosity in sandstone from the Tarim and Junggar basin depocenters was reduced principally by burial compaction and that the rate of porosity reduction was highest for lithic-rich samples.
normalized REE patterns for the pillow basalts are LREE-depleted [(La(N)/Sm(N))(ave)=0.70], similar to patterns for the mean diabase composition for the Oman ophiolite and LREE-depleted basalts of the Band-e-Zeyarat ophiolite of southern Iran. The REE patterns for the massive basalts are similar in general REE abundances to the pillow basalt patterns, but they are slightly LREEenriched [(La(N)/Sm(N))(ave)=1.09] and their patterns cross those of the pillow basalts. The REE patterns for the gabbros and diorites indicates that the crustal-suite rocks were most likely derived by a process of fractional crystallization from a common basaltic melt. This basaltic melt was most likely generated by approx. 20-25% partial melting of a simple lherzolite source and had REE concentrations of roughly 10x chondrite. A comparison between the results from the Khoy ophiolite and the data from other Iranian ophiolites reveals geochemical evidence to suggest a tectonic link between the Khoy ophiolite and the rest of the Iranian ophiolites. Our results suggest that Khoy ophiolite is equivalent t o the inner group of Iranian ophiolites (e.g. Nain, Shahr-Babak, Sabzevar, Tchehel Kureh and Band-e-Zeyarat) and was formed as a result of closure of the northwestern branch of a narrow Mesozoic seaway which once surrounded the Central Iranian microcontinent.
HOFMANN, P., RICKEN, W. SCHWARK, L. AND LEYTHAEUSER, D. 2001. Geochemical signature and related climatic-oceanographic processes for early Albian black shales: Site 417D, North Atlantic Ocean, Cretaceous Research, 22 (2), 243-257.
HE, K., NIE, Z., ZHAO, C., YE, N., ZHOU, Z., LE, C. AND TAI, D., 2000. Discovery of late Paleozoic Radiolaria i n ophiolitic melange, northeastern Jiangxi, China. Xiandai Dizhi = Geoscience, 14(1): 6-13.
ABSTRACT: A sediment sequence which may contain the early Albian OAE 1b was investigated in a deep-water (3800 m) openocean environment at Site 417D, western North Atlantic Ocean. Redox cycles, which contain black shale intervals and occur in the early Albian M. gracilis radiolarian Biozone, were studied in order t o show processes and climate-associated controlling factors during the deposition of early Albian sediments. The black shale intervals are characterized by the enhanced accumulation and preservation of marine-derived organic matter as determined by Rock-Eval pyrolysis and organic petrology. The presence of laminated sediments, the relationships between organic carbon, iron and total sulfur, pyrite size analysis and trace-metal enrichment indicate the periodic prevalence of anoxic conditions in the pore waters, which may at times have extended to the sediment/water interface. Changes in the mineralogical composition throughout the black shale-dominated interval, i.e., quartz content and clay-mineral assemblage, resulted in the variation of the major-element chemistry and probably reflect cyclic climatic changes in northern Africa combined with flooding of coastal lowlands during an overall transgressive phase in the early Albian. The geochemical signatures observed at different scales demonstrate a genetic link between the climate system on land and processes in the deep ocean during the deposition of black shales in deep-water environments of the western North Atlantic.
ABSTRACT: The radiolarian fossils of the Late Paleozoic were discovered by the authors for the first time in 1993 and 1996 from the ophiolitic melange in northeast Jiangxi Province, which has been taken as the Shuangqiaoshan Group of Middle Proterozoic and as the Zhitang Formation of Lower Sinian Series. The fossils and their geological ages are defined by 4 specialists who are Li Hongsheng, Feng Qinglai, Wu Haoruo and Wang Yujing. On the basis of the collection analysis of radiolarian-bearing siliceous rocks, the rock association in Zhangshudun and Dengshan, the petro-chemical and geochemical features, and the fossil characteristics, the authors think that the rocks are a set of abyssal basin sediments. Thus, the new discovery provides a scientific basis not only for defining property and age of the ophiolitic melange in northeast Jiangxi Province, but for redefining the tectonic affiliation of the "Banxi Group" and the geotectonic pattern of South China.
HENDRIX, M.S., 2000. Evolution of Mesozoic sandstone compositions, southern Junggar, northern Tarim, and western Turpan basins, Northwest China; a detrital record of the ancestral Tian Shan. Journal of Sedimentary Research, 70(3): 520-532.
ITAKI, T. AND HASEGAWA, S., 2000. Destruction of radiolarian shells during sample drying and its effect o n apparent faunal composition. Micropaleontology, 46(2): 179-185.
ABSTRACT: Sandstone compositional data can be a powerful tool in the interpretation of tectonic and climatologic influences on sedimentary basin fill, in addition to yielding important information about porosity in sandstone petroleum reservoirs. In order t o explore these relationships, a modified Gazzi-Dickinson pointcounting technique was used to analyze the composition of 1 4 3 Mesozoic sandstone samples from the southern Junggar, northern Tarim, and western Turpan basins of northwestern China. Results indicate that a Mesozoic, ancestral version of the Tian Shan physiographically separated the Junggar and Tarim basins and provided sand of very different composition to each basin. Mesozoic sandstone from the northern Tarim basin is diverse in composition and lithic-rich (Qm 41F 14L 45; Qp 42Lvm 26Lsm 32), is locally micaceous, and contains common radiolarian-chert grains and few dense accessory minerals. Inferred source rocks include upper Paleozoic alkali granite and metamorphic complexes, thick Silurian beddedchert sequences, and lower Paleozoic strata of a passive continental margin. In contrast, sandstone from the southern Junggar and western Turpan basins is uniformly volcanic-rich (Qm 21 F 21 Lt 58 ; Qp 13Lvm 68Lsm 19), and contains abundant dense accessory minerals and only local radiolarian chert and mica. Inferred principal source rocks are Devonian-Carboniferous andesitic arc volcanics. The effect of sampling scale on sandstone composition outweighs that of plate-tectonic setting. Samples were derived mostly from medium- and coarse-grained fluvial systems that likely drained only portions of the ancestral Tian Shan and hence preserve local source-rock signatures, rather than an integrated compositional signal that can be directly compared t o plate-tectonic petrofacies models. In addition, though Mesozoic basins of western China were most akin to broken foreland basins, Mesozoic sandstone is considerably more compositionally diverse and lithic-rich than that of modern or ancient broken foreland basins because of the variety of accreted terranes constituting the
ABSTRACT: Radiolarian concentration and faunal composition are compared between pairs of dried and wet sub-samples from 2 4 samples in sediment cores from the Japan Sea, in order to evaluate the alteration of radiolarian assemblages during the sample-drying process. Radiolarian shell count is reduced by nearly half after oven drying at 50°C as well as at ambient room temperature. In contrast, the shell count is unchanged by freeze drying. The reduction in radiolarian test count is probably caused by contraction and consolidation of the sediment. The reduction in shell count i s species-specific and results from the capacity of the shell to resist crushing owing to sediment contraction. Faunal composition definitely is altered by the drying process, especially in assemblages dominated by fragile species. The original faunal composition can be reconstructed from the observed faunal composition in dried material, based on the shell-strength of major species in a sample.
ITO, M., AITA, Y. AND HADA, S., 2000. New radiolarian age information for the Chrystalls Beach Complex, southwest of Dunedin, New Zealand. New Zealand Journal o f Geology and Geophysics, 43(3): 349-354. ABSTRACT: On the basis of lithology, structural style, and fossil evidence, northern and southern units are recognised within the Chrystalls Beach Complex exposed on the coast south of Akatore Creek, southwest of Dunedin, South Island, New Zealand. Radiolarians including Spongopallium sp. cf. S. contortum Dumitrica, Kozur and Mostler, Eptingium(?) sp., Norispongus(?) sp., and Pseudostylosphaera(?) sp. have been discovered in phosphatic nodules in metamorphosed argillite of the northern unit of the
27
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Bibliography - 2000-2001
complex. They are regarded as characteristic species of the Middle Triassic (Anisian-Ladinian). It has previously been known that the more weakly metamorphosed southern unit of the Chrystalls Beach Complex contains moderately well preserved Middle Triassic (Early Ladinian) radiolarian faunas. Together with forms of Tethyan affinity, the faunas in the southern unit contain non-Tethyan forms including Glomeropyle spp. Aita and Bragin, possibly of Southern Hemisphere high-latitude origin. These non-Tethyan forms are also known from the Mahinepua section of the Waipapa Terrane in Northland. Distinctive non-Tethyan forms such as Glomeropyle Aita and Bragin have not yet been found in the northern unit, the fauna o f which includes species that are known from the European Tethys area and which also occur in the southern unit.
cm and most of the sediments were siliceous oozes consisting o f radiolarian or diatomaceous tests. The shear strength measurements revealed that surface sediments deposited in recent times (0-10 cm) have a shear strength of 0-1 kPa; this value increases with depth, reaching 10 kPa at 40 cm deep. Older sediments have greater strength because of compaction. Water content varies in the wide range of 312-577% and decreases with depth. The clay minerals such as smectite and illite are dominant and show some control over water content. Wet density, specific gravity, and porosity do not indicate any notable variation with depth, thereby indicating a uniform, slow rate of sedimentation. The average porosity of sediments is 90.2%, specific gravity 2.18, and wet bulk density 1.12 g/cm 3 . Sediments exhibit medium to high plasticity characteristics, with the average plasticity index varying between 105% and 136%. Preliminary studies on postdisturbance samples showed an increase in natural water content and a decrease in undrained shear strength of sediments in the top 10- t o 15-cm layer.
KAMATA, Y., HISADA, K.I. AND LEE, Y.I., 2000. Late Jurassic radiolarians from pebbles of Lower Cretaceous conglomerates of the Hayang Group, southeastern Korea. In: S. Otoh and J. Lee Byung (Editors), The Korean and Japan Structure and Tectonics Group meeting. Second conference of the Korean and Japan Structure and Tectonics Group. Hokkaido, Japan. Aug. 19-23, 1999. Geoscience Journal (Seoul). 4; 3, Pages 165-174. 2000.
KIESSLING, W. AND FLUGEL, E., 2000. Late Paleozoic and Late Triassic limestones from north Palawan block (Philippines): Microfacies and Paleogeographical implications. Facies. 2000; -(43): 39-77.
ABSTRACT: Permian to Late Jurassic radiolarians were obtained from granules and pebbles in conglomerates of the Donghwachi and Gisadong formations of the Lower Cretaceous Hayang Group, southeastern Korea. Radiolarian faunas and the petrologic character of the pebbles resemble those of Jurassic accretionary complexes of East Asia. Considering lines of evidence such as the lithologic characters of pebbles, affinity of the radiolarian faunas, reconstructed paleocurrent direction in the Hayang Group, and the paleogeographic position of southwestern Japan, it may be inferred that these pebbles were derived from the accretionary complexes mainly of southwestern Japan and the Far East. New evidence f o r the occurrence of Late Jurassic radiolarians in the Gisadong Formation suggests that radiolarian-bearing pebbles would be not only chert but also siliceous shale or shale of the Jurassic accretionary complexes, and gives an exhumation age for the latest accreted units of the complexes.
ABSTRACT: Selected Late Paleozoic and Triassic limestone exposures were studied on northern Palawan Island, Philippines, with regard to microfacies, stratigraphy and facies interpretation. Although some of the outcrops were already reported in literature, we present the first detailed microfacies study. Late Paleozoic carbonates in the El Nido area are represented by widley distributed Permian and locally very restricted Carboniferous limestones. Of particular interest is the first report of Carboniferous limestones in the Philippines dated by fossils. Fusulinids indicate a 'Middle' Carboniferous (Moscovian-Kasimovian) age of the Paglugaban Formation only known from Paglugaban Island. The Permian Minilog Formation consists mostly of fusulinid wackestones and dasycladacean wacke-/packstones. Fusulinid datings (neoschwagerinids and verbeekinids) provide a Guadalupian (Wordian-Capitanian) age. The depositional setting of the Middle Permian carbonates corresponds to a distally steepened ramp with biostromes built by alatoconchid bivalves locally associated with richthofeniid brachiopods. Late Triassic limestones occur in isolated exposures on and around Busuanga Island (Calamian Islands). The age of the investigated carbonates is Rhaetian based on the occurrence of Triasina hantkeni Majzon. Microfacies data indicate the existence of reefs (Malajon Island) and carbonate platforms (Kalampisanan Islands, Busuanga Island, Coron Island). Reef boundstones are characterized by abundant solenoporacean red algae, coralline sponges and corals. Platform carbonates yield a broad spectrum of microfacies types, predominantly wacke- and packstones with abundant involutinid foraminifera and some calcareous algae. These facies types correspond to platform carbonates known from other parts of Southeast Asia (Eastern Sulawesi and Banda Basin; Malay Peninsula and Malay Basin). The Philippine platform carbonates were deposited on and around seamounts surrounded by deeper water radiolarian cherts. The new data on facies and age of the Philippine Permian and Triassic carbonates contradict a close paleogeographical connection between the North Palawan Block and South China and arise problems for the currently proposed origin of the North Palawan Block at the paleomargin of South China. We hypothesize that North Palawan was part of the Indochina Block during the Carboniferous and Permian, separated from the Indochina Block during the Middle Permian and collided with the South China Block in the Late Cretaceous.
KEMKIN, I.V. AND KEMKINA, R.A., 2000. Jurassic-Early Cretaceous biostratigraphic cherty and terrigenous deposits of the Dalnegorsk ore region (Southern Sikhote-Alin). Geology of the Pacific Ocean. 2000; 15(1): 85-106 ABSTRACT: The article presents the results of biostratigraphic investigations of cherty and terrigenous deposits in the Dalnegorsk ore region. Twelve radiolarian assemblages, successively replacing one another, characterizing Upper Pliensbachian-Lower Toarcian, Lower-Middle Toarcian, Upper Toarcian-Middle Aalenian, Upper Aalenian-Lower Bajocian, Middle Bajocian, Upper Bajocian-Lower Bathonian, Middle Bathonian-Lower Callovian, Middle OxfordianLower Kimmeridgian, Middle-Upper Kimmeridgian, Lower-Middle Tithonian, Upper Tithonian and Lower Valanginian-Lower Barremian deposits of the cherty-terrigenous section are distinguished. A brief description of the complexes and photographs of Jurassic-Early Cretaceous radiolarians are given.
KEMKIN, I.V. AND RUDENKO, V.S., 2000. New datings of cherts from the Samarka accretionary wedge (South SikhoteAlin). Geology of the Pacific Ocean, 15(4): 715-729. ABSTRACT: New data on the structure and age of cherty slides from the Samarka accretionary wedge, as well as on the age o f chert-matrix transitive layers are considered. The revealed seven radiolarian assemblages of different age are briefly characterized. Five of them in age ranging from Mid Triassic to Mid Jurassic correspond to a cherty part of the described cross-section, another two, also Mid Jurassic, to a terrigenous one. Photos of Triassic and Jurassic radiolarians are provided.
KINCAID, E., THUNELL, R.C., LE, J., LANGE, C.B., WEINHEIMER, A.L. AND REID, F.M.H., 2000. Planktonic foraminiferal fluxes in the Santa Barbara Basin: Response t o seasonal and interannual hydrographic changes. Deep Sea Research Part II: Topical Studies in Oceanography, 47(5-6): 1157-1176.
KHADGE, N.H., 2000. Geotechnical properties of surface sediments in the INDEX area. Marine Georesources and Geotechnology. 2000; 18(3): 251-258
ABSTRACT: Results of a three-year time-series sediment trap experiment in the Santa Barbara Basin indicate linkages between water-column dynamics and variations in plankton fluxes on both seasonal and interannual time scales. The two-week collection interval utilized for this study allows evaluation of high-frequency changes in the production and flux of planktonic foraminifera, which are compared to those of siliceous microorganisms (diatoms, radiolaria and silicoflagellates). Annual hydrographic conditions in Santa Barbara Basin are influenced by seasonal changes in
ABSTRACT: As a part of the environmental impact assessment studies, geotechnical properties of sediments were determined in the Central Indian Basin. The undrained shear strength and index properties of the siliceous sediments were determined on 20 box cores of uniform dimension collected from various locations in five preselected sites. The maximum core length encountered was 4 1
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Bibliography - 2000-2001 direct influence of the California Current and associated upwelling system. Using age models based on combination of calcareous nannofossil and radiolarian data and magnetostratigraphic chron boundaries, ages were assigned to the events, thus allowing investigations of their spatial and temporal distribution. Three o f the events have been identified as clearly diachronous; two of these seem to represent examples of latitudinal immigrations. The evolutionary activity in the neogloboquadrinid clade on the California margin appears centered around 2.1 Ma, with most of the events occurring between 2.5 and 1 Ma. This interval was a time o f major climate change. No events have occurred after 0.7 Ma supporting the notion that the extreme climate variations of the Late Pleistocene inhibited speciation. Assignment of ages to events defining boundaries of the California margin (CM) zones of Kennett and others has enabled us to compare this zonation with the standard planktonic foraminiferal zonal schemes. Seven of the neogloboquadrinid events occurred during the last 2.5 myr, suggesting that the time resolution of the CM zones (including the coiling dominance zones of Lagoe and Thompson) during this interval is at least twice that of the standard planktonic foraminiferal zonation. The remaining Pliocene is divided only into two CM zones compared to six standard planktonic foraminiferal zones. One of the Pleistocene neogloboquadrinids is formally described as a new species.
insolation, the wind field and source waters. This study includes periods of weak to moderate El Nino conditions followed by a transitional period to a non-El Nino state. Planktonic foraminiferal fluxes and species turnover are related to seasonal and interannual changes in source waters and water column conditions. Globigerina bulloides, G. quinqueloba and Neogloboquadrina pachyderma (dextral) dominate the planktonic foraminiferal population in this location and are present throughout the year. Globigerina bulloides and G. quinqueloba have similar flux patterns, and highest fluxes occur in association with diatom blooms. The flux patterns of G. bulloides and G. quinqueloba in general are inversely related to that of N. pachyderma (dextral). Globigerina quinqueloba seems t o respond earlier to the onset of upwelling than G. bulloides. Three temperature-limited species, Neogloboquadrina dutertrei, Orbulina universa and Globigerinoides tuber, are present in lower numbers and show more restricted seasonal ranges. In the thermal regime o f the Santa Barbara Basin, N. dutertrei, like O. universa, disappears during upwelling. Neogloboquadrina dutertrei occurs in highest abundance when the water column is thermally stratified and there is a well developed deep chlorophyll maximum. Increased fluxes o f Globigerinoi tuber the most thermally restricted of the dominant species in the basin, are associated with the presence of warm oceanic diatoms and warm-water radiolarians. Total planktonic foraminiferal fluxes were lower in 1995 than during the previous two years, which were characterized by El Nino conditions.
KURIHARA, T., 2000. Devonian radiolarians from the Upper Ise River area of the western part of the Hida Gaien Belt, Izumi Village, Fukui Prefecture, central Japan. Fossils, 67: 32-43.
KOJIMA, S., AND SAITO, M. 2000. Triassic and Jurassic radiolarians from the Tokuyama area, Mino terrane, central Japan. Bulletin of the Geological Survey of Japan 51: 143165.
ABSTRACT: Moderately well-preserved Early to Middle Devonian (Emsian to Eifelian) radiolarians were recovered from shaly portions of alternating sandstone and shale exposed at the Upper Ise River area of the western part of the Hida Gaien Belt, in Izumi Village, Fukui Prefecture, central Japan. This radiolarian-bearing clastic sequence differs lithologically from the limestone-dominant sequence previously defined as the Kamianama Group and thus the stratigraphic subdivision of the Devonian in this area should be revised. The radiolarian fauna of this clastic sequence i s characterized by an abundant occurrence of species belonging t o the genera Palaeoscenidium, Deflantrica, and Pactarentinia, and i s comparable with that of the late Early to early Middle Devonian Glanta fragilis and Protoholoeciscus hindea zones proposed in the Yokokurayama area of the Kurosegawa Belt. The newly obtained microfossil and lithostratigraphic data strongly support that the Devonian strata consisting of both clastic and limestone-dominant sequences of the Ise area are correlative with the Yoshiki and Fukuji Formations of the Fukuji area, respectively.
KOJIMA, S., KEMKIN, I.V., KAMETAKA, M. AND ANDO, A., 2000. A CORRELATION OF ACCRETIONARY COMPLEXES OF SOUTHERN Sikhote-Alin of Russia and the inner zone of Southwest Japan. In: S. Otoh and J. Lee Byung (Editors), The Korean and Japan Structure and Tectonics Group meeting. Second conference of the Korean and Japan Structure and Tectonics Group. Hokkaido, Japan. Aug. 1923, 1999. Geoscience Journal (Seoul). 4; 3, Pages 175-185. ABSTRACT: This paper briefly describes the geology of southern Sikhote-Alin of Russia and the Inner zone of Southwest Japan, and presents a new correlation model in which the Samarka terrane (sensu stricto), Udeka Formation, Sebuchar Formation and Kalinovka ophiolite in Sikhote-Alin are considered as northern extensions of the Mino-Tamba terrane, Hikami Formation, Kozuki Formation, and Yakuno ophiolite in Southwest Japan, respectively. This correlation is based on the similarities in lithology, age, faunal assemblage, and structural relationship between them. The Samarka and Mino-Tamba terranes consists of Jurassic accretionary complexes including Permian greenstone-limestone complex, Permian to Lower Jurassic radiolarian bedded chert, Jurassic clastic rocks, and Jurassic melanges. The Udeka and Hikami formations are composed mainly of greenish gray sandstone with minor shale intercalations yielding Permian radiolarians. The Sebuchar and Kozuki formations are characterized by basalts accompanied with shale, limestone and chert. The limestone includes Carboniferous fusulinaceans, while Permian radiolarians occur in the chert. The Kalinovka and Yakuno ophiolites consist of a series of ultramafic t o mafic igneous rocks with an ophiolitic succession. Since the ages o f these ophiolites have not been clearly established, we correlate them on the basis of their lithology and tectonic positions. These units form a stack of nappes from the lower to upper horizons in the following order: Mino-Tamba terrane, Hikami Formation, Kozuki Formation, and Yakuno ophiolite in Japan, and Samarka terrane (sensu stricto), Udeka Formation, Sebuchar Formation, and Kalinovka ophiolite in Russia. This correlation supports the reconstruction model of Japan before the opening of the Sea o f Japan proposed by Yamakita and Otoh (1999).
KURIHARA, T. AND SASHIDA, K., 2000. Early Silurian (Llandoverian) radiolarians from the Ise area of the Hida 'Gaien' Belt, central Japan. Paleontological Research, 4(2): 147-162. ABSTRACT: A moderately well-preserved Llandoverian (early Early Silurian) radiolarian fauna has been discovered from the Ise area o f the Hida 'Gaien' Belt, in Izumi Village, Fukui Prefecture, central Japan. This is the oldest known radiolarian fauna in Japan, and was recovered from calcareous nodules in the siliceous shale portion o f a sedimentary sequence consisting of siliceous shale, alternating tuffaceous sandstone and shale, and tuffaceous sandstone. The fauna contains Haplotaeniatum tegimentum, Syntagentactinia afflicta, S. excelsa, Oriundogutta sp., Inanihella sp., Auliela sp., Palaeoephippium? sp., and Orbiculopylorum sp. This fauna i s characterized by an abundance of species in the genera Haplotaeniatum, Syntagentactinia and Oriundogutta, and i s comparable with the early to middle Llandoverian Haplotaeniatum tegimentum Assemblage and its equivalents in the southern Urals, Germany, and Nevada. Seventeen species of radiolarians belonging to 12 genera were systematically investigated.
KUCERA, M. AND KENNETT, J.P., 2000. Biochronology and evolutionary implications of late Neogene California margin planktonic foraminiferal events. Marine Micropaleontology, 40(1-2): 67-81.
KURIHARA, T. AND SASHIDA, K., 2000. Taxonomy of Late Silurian to Middle Devonian radiolarians from the Kuzurya Lake district of the Hida Gaien Belt, Fukui Prefecture, central Japan. Micropaleontology, 46(1): 51-71.
ABSTRACT: The biochronology of eight events (first or last occurrences) among species of the planktonic foraminifer Neogloboquadrina plexus have been examined in six Pliocene t o Quaternary deep-sea sequences drilled during ODP Leg 167 off the coast of California. The sites form a meridional transect along the California margin from 31°N to 41°N, covering an area under the
ABSTRACT: Moderately well-preserved late Late Silurian (Ludlowian to Pridolian) to early Middle Devonian (Eifelian) radiolarians were recovered from clastic rock sequences in the Kuzuryu Lake district of the Hida Gaien Belt, Fukui Prefecture, central Japan. These radiolarians are identical to the faunas of the following four assemblages: Zadrappolus yoshikiensis (Late Silurian;
29
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Ludlowian to Pridolian), Pseudospongoprunum sagittatum (latest Silurian; Pridolian), Zadrappolus sp. aff. Z. spinosus (latest Silurian to earliest Devonian; Pridolian to Lochkovian) and Pactarentinia holdsworthi (Early to Middle Devonian; Emsian to Eifelian) Assemblages. These radiolarian faunas from the Hida Gaien Belt are correlative with those of the Kurosegawa Belt (Outer Belt o f southwest Japan). Silurian radiolarian faunas from the Hida Gaien and Kurosegawa Belts are similar to those from West Junggar in westernmost China. The Early and Middle Devonian radiolarian faunas in Japan are different from those in eastern Australia in that the Japanese faunas characteristically contain 'shelled Palaeoscenidiidae'. Thus, based on radiolarian faunal similarity, Silurian and Devonian radiolarian-bearing rock sequences in Japan are inferred to have accumulated in the sea nearer to the SinoKorean Continent than to eastern Australia in the low latitude o f Gondwana. Radiolarians of 26 species belonging to 13 genera were systematically investigated. Ten new species are described: Palaeoscenidium simplum, Palaeoscenidium hakogasensis, Palaeoscenidium fragilis, Deflantrica furutanii, Pactarentinia intermedia, Pactarentinia igoi, Tlecerina isensis, Ceratoikiscum izumiensis, Palaeopyramidium ramosum and Palaeoumbraculum hidense.
MARTINI, R., ZANINETTI, L., VILLENEUVE, M., CORNEE, J.J., KRYSTYN, L., CIRILLI, S., DE, W.P., DUMITRICA, P. AND HARSOLUMAKSO, A., 2000. Triassic pelagic deposits of Timor: Palaeogeographic and sea-level implications. Palaeogeography Palaeoclimatology Palaeoecology, 160(12): 123-151. ABSTRACT: In West Timor, Triassic deposits are found in the Parautochthonous Complex, as well as in the Allochthonous series of Sonnebait. A detailed biostratigraphic investigation, integrating field observations and facies analysis, allowed the reconstruction o f a synthetic lithostratigraphic succession for the Upper Triassic; a stratigraphic transition from Carnian shales to Upper NorianRhaetian limestones is also shown by this study. The fossil content predominantly originates from an open marine environment; lithostratigraphic Units A-E are dated on the basis of radiolaria and palynomorphs, and Unit H, on ammonites and conodonts. The presence of pelagic bioclasts, together with normal grading, horizontal laminations, and current ripples, is indicative of a distal slope to basin environment. The ammonite rich condensed limestone of Unit H was deposited on a 'pelagic carbonate plateau' exposed t o storms and currents. The organic facies have been used as criteria for biostratigraphy, palaeoenvironmental interpretation, and sequence stratigraphy. The palaeontological analysis of the Triassic succession of West Timor is based on the investigation of radiolaria and palynomorphs, in the marls and limestones of Units A-E, and also on ammonites and conodonts in the condensed limestone o f Unit H. Units A and B are Carnian (Cordevolian) in age, based on the occurrence of the palynomorph Camerosporites secatus, associated with 'Lueckisporites' cf. singhii, Vallasporites ignacii, Patinosporites densus and Partitisporites novimundanus. Unit C is considered as Norian, on the basis of a relatively high percentage of Gliscopollis meyeriana and Granuloperculatipollis rudis. Unit D contains significant palynomorphs and radiolaria; the organic facies, characterized by marine elements, is dominated by the Norian dinocysts Heibergella salebrosacea and Heibergella aculeata; the radiolaria confirm the Norian age. They range from the lowermost Norian to the lower Upper Norian. Unit E also contains radiolaria, associated in the upper part with the well-known marker of the Upper Norian, Monotis salinaria. For Unit E, the radiolaria attest to a Lower to Upper Norian age based on the occurrence of Capnodoce and abundant Capnuchosphaera; the upper part is Upper Norian t o Rhaetian based on the presence of Livarella valida. Finally, the blocks of condensed limestone with ammonites and conodonts o f Unit H allowed the reconstruction of a synthetic stratigraphic succession of Upper Carnian to Upper Norian age. Our stratigraphic data lead to the suggestion that the Allochthonous complex, classically interpreted as a tectonic melange of the accretionary prism of the Island Arc of Banda, is a tectonically dismembered part of a Triassic lithostratigraphic succession.
KUWAHARA, K., 1999. Middle-Late Permian radiolarian assemblages from China and Japan. In A. Yao, Y. Ezaki, W. C. Hao and X. P. Wang (Editors) Biotic and Geological Development of the Paleo-Tethys in China pp. 43-54, Peking University Press, Peking. KUWAHARA, K. AND YAO, A., 2000. Analysis of origination and extinction of radiolarian fossil assemblages from the Mino Belt. In: Anonymous (Editor), Abstracts of Geoinforum-2000 annual meeting. Japanese Society for Geological Data Processing [in cooperation with] Osaka City University, Department of Geosciences. Osaka, Japan. 2000. Joho Chishitsu = Geoinformatics. 11; 2, Pages 9091. LI, Y., JIA, C., HAO, J., WANG, Z., ZHENG, D. AND PENG, G., 2000. Radiolarian fauna found from Tieshidas Group i n East Kunlun. Chinese Science Bulletin. 45(10): 943-946. ABSTRACT: The Tieshidas Group in Qimantag, a branch of the East Kunlun Mountains, was classically considered the Caledonian basement, and classified into Middle-Upper Ordovician, Upper Ordovician or simply Lower Paleozoic. The radiolarian fauna was found, for the first time, from a chert block in the Tieshidas Group at Yaziquandaban (Pass) north to Ayakum Lake. They are Astroentactinia ? mirousi Gourmelon, As. cf biaciculata Nazarov, Archocyrtium cf. diductum Deflandre, Ar. aff. diductum Deflandre, Deflandrellium? sp., Entactinia vulgaris Won, En. cf. additiva Foreman, En.? sp., Entactinosphaera palimbola Foreman, Pylentonema? sp., Triaenosphaera sp. and Tr.? sp. The geological age of this radiolarian fauna is Early Carboniferous. Evidently, the classical interpretation about the age of Tieshidas Group needs t o be checked and modified. Except the Ordovician proved with the formerly discovered fossils, it also includes, at least, Lower Carboniferous rocks. There was still an oceanic basin at Qimantag during Early Carboniferous (and even a long geological time after then). Qimantag is not a Caledonian fold belt, and the Tieshidas Group is not the Caledonian basement.
MATSUOKA, A. AND YANG, Q., 2000. A direct correlation between North American and Japan-Pacific radiolarian zonal schemes for the Upper Jurassic. In: L. Hall Russell and L. Smith Paul (Editors), Advances in Jurassic research 2000; proceedings of the Fifth international symposium on the Jurassic system. Trans Tech Publications. Zurich, Switzerland. 2000. MCCARTHY, A.J., JASIN, B. AND HAILE, N.S., 2000. Middle Jurassic radiolarian chert, Indarung, Padang District, and its implications for the tectonic evolution of western Sumatra, Indonesia. Journal of Asian Earth Sciences, 19(12): 31-44.
LIU, Y., 2001. Early Carboniferous radiolarian fauna from Heiyingshan south of the Tianshan Mountains and its geotectonic significance, Acta Geologica Sinica English Edition, 75 (1), 101-108, 101-108.
ABSTRACT: Radiolaria from chert in the Indarung Area belong t o the Transhsuum hisuikyoense Zone, indicating an Aalenian, lower Middle Jurassic, age. Carbonate in the area has been dated as Upper Jurassic to Lower Cretaceous from the occurrence of Lovcenipora, and overlying tuff has given a radiometric K/Ar age of 105 ± 3 (Albian, uppermost Lower Cretaceous). The chert and carbonate are probably in tectonic contact, with the chert faulted into the limestone during ENE-directed compression. This comprises one o f the best dated occurrences of allochthonous material in Sumatra and confirms the accretion of oceanic material along the Sunda margin during Mid- to Late-Cretaceous times.
ABSTRACT: Abundant and well-preserved fossil radiolarians found from the Artencasher Formation, Heiyingshan of Baicheng, County, Xinjiang Uygur Autonomous Region, are identified, including 1 5 species and 2 unnamed species in 9 genera. The fauna is dominated by the Family Entactiniidae of Spumellaria. According to the faunal characteristics, the radiolarians may be divided into five assemblages, namely, the Triaenosphaera sicarius , Entatinosphaera palimbola, Entactinia vulgaris, Belowea cf. variabilis and Archocyrtium sp assemblages. The fauna may be correlated with that from the Early Carboniferous of Frankenwald and Rein in Germany. Thus, ophiolite was formed in the Carboniferous, while the age of collision between the Iii plate and the Tarim plate is Early Carboniferous.
MEKIK, F.A., 2000. Early Cretaceous Pantanelliidae (radiolaria) from Northwest Turkey. Micropaleontology, 46(1): 1-30. 30
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Bibliography - 2000-2001 Densification of the decollement zone is caused primarily by collapse of pore spaces between clay minerals and secondarily by collapse of radiolarian porosity, mineral phase changes, and zeolite precipitation. Previous coring results and, arguably, the seismic reflection data indicate that the decollement remains localized in an interval of low-density radiolarian claystone. Weakening of this smectite-rich lithology during shear explains the tendency of the decollement to remain localized in its initial position. An inadvertent two-hole hydrologic test conducted during LWD operations indicates significantly higher permeability over the scale of 50 m than that inferred previously from single borehole tests.
ABSTRACT: During Mesozoic time Turkey was situated within the Tethyan Realm. The stratigraphic section KEL of pelagic sequences on the Sakarya Continent (=SC) (northwest Turkey) is latest Tithonian-Berriasian in age based on radiolarians and co-occurring calpionellids and calcareous nannofossils. Section PEM, from fragmented slope deposits of SC, is defined as late Valanginian in age for the first time based on its radiolarians. Pantanelliids comprise 25% of Berriasian and 39% of late Valanginian radiolarian faunas in these sections. Two new genera, Cana and Denize, and six new species, Cana elegans, Cecrops anatolicus, Cecrops blomei, Cecrops (?) pessagnoi, Denize magnifica, and i are described.
MIHALYNUK, M.G., ERDMER, P., GHENT, E.D., ARCHIBALD, D., FRIEDMAN, R.M., CORDEY, F. AND JOHANNSON, G.G.: Age Constraints for Emplacement of the Northern Cache Creek Oceanic Crust and Implications of Youngest Blueschist Metamorphism; Geological Society o f America Bulletin, in press.
NIGRINI, C. AND SANFILIPPO, A., 2000. Paleogene radiolarians from Sites 998, 999, and 1001 in the Caribbean. Proceedings of the Ocean Drilling Program: Scientific Results, 165: 57-81. ABSTRACT: The Paleogene sequences from three sites in the Caribbean were examined for radiolarians. In general, samples are highly lithified, requiring lengthy and repetitive cleaning procedures, and the assemblages are usually fragmented and/or partially dissolved. Both abundances and preservation of the assemblages vary considerably from site to site and within a single site; even within a single sample more than one degree of preservation was observed. It was possible, however, to construct at least partial stratigraphies for each of the three sites. Because the abundance o f radiolarians is high even in extremely poorly preserved assemblages, we conclude that the differences in biogenic silica preservation are the result of postdepositional processes and not productivity. In both Sites 999 and 1001, near the Paleocene/Eocene boundary (Bekoma bidartensis Zone [RP7]), there is a short interval in which the abundance and preservation state o f the radiolarians improves relative to overlying and underlying assemblages. In each case the intervals corresponds to the level, identified by calcareous microfossils, as representing changes in paleoceanographic conditions associated with the late Paleocene thermal maximum.
MISIK, M. AND JABLONSKY, J., 2000. Lower Triassic quartzites of the Western Carpathians: Transport directions, source of clastics. Geologica-Carpathica. 51(4): 251-264. ABSTRACT: The possibility of localizing the source area for the Lower Triassic (Scythian) quartzites and sandstones (Luzna Fm.) was checked. Cross-bedding measurements show the transport from the Carpathian foreland, from the NW and N (the same as in the Eastern Alps). The source area could be in the eastern part o f the Bohemian Massif (now subducted under the Carpathians), or in the Armorican Massif, if the supposed large left-lateral shift of the Central Western Carpathians took place. The sedimentary environment can be characterized as fluvial braidplain of ephemeral sandy-pebbly streams with intervals of eolian transport. Rare intercalations of psephitic clasts contain only the most resistent rocks: vein quartz, quartz porphyries (rhyolites) with their pyroclastics, rare intermediary volcanites, postvolcanic products as jaspers and hematitic quartzites, graphitic metaquartzites, radiolarian lydites, silicified wood of Dadoxylon sp., limnosilicites with pollen grains and a single silicite with ostracods. Various tourmalinitic rocks are the most promissing for the identification o f the provenance area.
NISHIMURA, Y., COOMBS, D.S., LANDIS, C.A. AND ITAYA, T., 2000. Continuous metamorphic gradient documented by graphitization and K-Ar age, southeast Otago, New Zealand. American Mineralogist, 85(11-12): 1625-1636.
MOORE, J.C. AND OCEAN DRILLING PROGRAM, L.A., SHIPBOARD SCIENTIFIC PARTY, 2000. Synthesis of results; logging while drilling, northern Barbados accretionary prism. In: J.C. Moore et al. (Editors), Proceedings of the Ocean Drilling Program, scientific results, northern Barbados accretionary prism, logging while drilling; covering Leg 171A of the cruises of the drilling vessel JOIDES Resolution; Balboa, Panama, t o Bridgetown, Barbados; sites 1044-1048, 17 December 1996-8 January 1997. Proceedings of the Ocean Drilling Program, Scientific Results. 171A; Texas A & M University, Ocean Drilling Program. College Station, TX, United States.
ABSTRACT: The Chrystalls Beach-Brighton coastal section, southwest of Dunedin, New Zealand, exposes Otago Schist, including the weakly metamorphosed Triassic accretionary melange of the Chrystalls Beach Complex and higher-grade rocks of a largely felsic, arc-derived provenance. Melange zones contain pelagic sediments, some of which are manganiferous, and metabasites. The grade o f metamorphism increases progressively from southwest t o northeast. Four mineral zones are recognized largely on the basis o f mineral assemblages in psammitic and semipelitic rocks: pumpellyite-chlorite, pumpellyite-actinolite, epidote-actinolite, and biotite. d002 data for carbonaceous material, b 0 values for phengite, and metamorphic phengite K-Ar ages are reported for 32 pelitic and semipelitic samples. Remarkably tight correlations are revealed between d 002 for progressively graphitized carbonaceous material, K-Ar ages that range from 184.6 to 138.7 Ma, and linear distance along the section. Both the d 002 values and the K-Ar ages decrease progressively toward the northeast through the four mineral zones and with progressive textural changes. All rocks cropping out in the section have undergone a coherent episode of progressive metamorphism associated with terrane collision and have not been disturbed by any later major displacements. A convex trend f o r phengite b 0 values plotted against advancing graphitization suggests P/T conditions during metamorphism as in the highpressure intermediate facies series. The age of the metamorphic peak is inferred to be 175-155 Ma (Middle to Late Jurassic), with cooling to the mica closure temperature at 155-135 Ma (Late Jurassic to Early Cretaceous). Unloading, denudation, and cooling were accompanied by localized hydrothermal events. The oldest covering strata were deposited at ca. 100 Ma and denudation was completed by ca. 75-80 Ma. Middle Triassic radiolarian nodules in melange zones are dated as preceding the metamorphic peak by about 65 Ma. Associated turbidities contain suspected late Middle to early Late Triassic tube fossils.
ABSTRACT: Leg 171A collected logging while drilling (LWD) data at three sites in the northern Barbados accretionary prism and two in the section just seaward of the prism. These borehole logs, plus extensive information from previous Deep Sea Drilling Project and Ocean Drilling Program legs and a three-dimensional (3-D) seismic survey, provide new insights on the evolution of this accretionary prism. Application of multivariate statistical methods to the LWD data quickly, reliably, and objectively define logging units that correlate well with the lithologic units from cored holes. Calculation of resistivity-based porosities allowed estimation of borehole velocities that were not directly measured by the LWD tools. LWD data combined with previous coring results indicate that a lowdensity radiolarian claystone characterizes the proto-decollement zone, facilitates normal faulting in the incoming section, and localizes the decollement zone beneath the accretionary prism. Site 1045 data indicate that a low-density interval also characterizes the strong negative-polarity seismic reflections from the decollement zone. Both the individual LWD sites and an inversion o f the 3-D seismic data for density indicate that the low-density decollement zone progressively consolidates with underthrusting. A northeasterly trending band of negative-polarity reflections in the decollement zone is an exception to this progressive densification process and shows anomalously low density caused by an arrested consolidation. Fluid flow from depth may account for the arrested consolidation of the northeasterly band of anomalously low density.
NOBLE, P. AND AITCHISON, J., 2000. Early Paleozoic radiolarian biozonation. Geology (Boulder), 28(4): 367370. 31
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ABSTRACT: Current knowledge of early Paleozoic radiolarians permits the recognition of faunal assemblages and zones that constitute a biozonation. This new zonation utilizes robust and relatively common, easily recognized morphotypes. It will facilitate rapid acquisition of previously unavailable age constraints f o r marine siliceous sedimentary successions in hitherto poorly understood early Paleozoic orogenic collages.
ORCHARD, M.J., CORDEY, F., RUI, L., BAMBER, W., STRUIK, L.C. AND SANO, H., 2001: Paleontological constraints on the paleogeography of the Carboniferous t o Jurassic Cache Creek Terrane in central British Columbia; Canadian Journal of Earth Sciences, in press. OZVOLDOVA, L., JABLONSKY, J. AND FRANTOVA, L., 2000. Upper Jurassic radiolarites of the Czertezic succession and comparison with the Kysuca succession in the eastSlovak part of the Pieniny Klippen Belt (Western Carpathians, Slovakia). Geologica Carpathica, 51(2): 109119.
NOBLE, P. J., AND MALETZ, J. 2000. Radiolaria front the Telychian (Llandovery, Early Silurian) of Dalarna, Sweden. Micropaleontology 46 (3): 265-275. ABSTRACT: A Haplotaeniatum-dominated radiolarian fauna has been discovered in Llandoverian (Early Silurian) strata of the Scandinavian platform, Dalarna, Sweden. As one of six occurrences of this fauna world-wide, it supports the premise that many elements in the Haplotaeniatum Assemblage have a wide geographic distribution and will be of significance in building an Early Silurian radiolarian biostratigraphic scheme with global application. In addition to Haplotaeniatum, this fauna contains palaeoscenidiid and secuicollactine taxa that are known only from one other locality, the Cape Phillips Formation, Canadian Arctic. These taxa may prove t o be fairly cosmopolitan and biostratigraphically useful as more data from other localities are collected. Two new genera, Labyrinthosphaera and Gyrosphaera, and three new species, Labyrinthosphaera macdonaldi, Gyrosphaera siljanensis, and Gyrosphaera raneatela, are described herein. Labyrinthosphaera has a multi-layered labyrinthine meshwork and with six or more t r i bladed spines. Gyrosphaera has a labyrinthine meshwork and displays spiraliform layering, similar to that described in Haplotaeniatum, indicating a close phylogenetic link between these two Llandoverian taxa. Further data from additional localities i s needed to determine the potential diachroneity of a global Haplotaeniatum acme zone, and to identify additional taxa whose first and last occurrences may be used as biostratigraphic datums for the Llandoverian.
ABSTRACT: In the more shallow-water Czertezic Succession, the stratigraphical interval of maximum deepening of the Pieniny sedimentary basin in the Upper Jurassic is not represented by typical radiolarite sequences with radiolarians, representing middle Callovian-early Oxfordian to late Oxfordian-early Kimmeridgian (U.A.Zone 8-U.A.Zone 10), as we can observe in the deep-water Kysuca Succession, but by radiolarian limestones with radiolarian cherts and irregular layers of radiolarites. Their sedimentation began here only in the Oxfordian. The radiolarian microfauna is o f middle-late Oxfordian to late Oxfordian-early Kimmeridgian age (U.A.Z.9-U.A.Z.10). In four sections in the locality Litmanova f i f t y eight taxons and one new species Archaeospongoprunum mizutanii Ozvoldova, n.sp. were identified in the assemblages. The high content of spumellarians (70-80 %) could reflect the paleogeographical and paleoceanographical conditions of sedimentation.
PALFY, J., MORTENSEN, J.K., CARTER, E.S., SMITH, P.L., FRIEDMAN, R.M. AND TIPPER, H.W., 2000. Timing the end-Triassic mass extinction; first on land, then in the sea? Geology (Boulder), 28(1): 39-42. ABSTRACT: The end-Triassic marks one of the five biggest mass extinctions, but current geologic time scales are inadequate f o r understanding its dynamics. A tuff layer in marine sedimentary rocks encompassing the Triassic-Jurassic transition yielded a U-Pb zircon age of 199.6 ± 0.3 Ma. The dated level is immediately below a prominent change in radiolarian faunas and the last occurrence o f conodonts. Additional recently obtained U-Pb ages integrated with ammonoid biochronology confirm that the Triassic Period ended ca. 200 Ma, several million years later than suggested by previous time scales. Published dating of continental sections suggests that the extinction peak of terrestrial plants and vertebrates occurred before 200.6 Ma. The end-Triassic biotic crisis on land therefore appears to have preceded that in the sea by at least several hundred thousand years.
O'CONNOR, B. 2000. Stratigraphic and geographic distribution of Eocene Miocene Radiolaria from the southwest Pacific. Micropaleontology 46 (3): 189-228. ABSTRACT: The known stratigraphic and geographic ranges of 5 0 recently erected species and five recently erected genera o f Radiolaria, originally described from the New Zealand area (from the Mahurangi Limestone and Puriri Formation in Northland, and the Oamaru Diatomite in the South Island), are documented. The data i s significantly updated from that presented in the original descriptions, and includes information from several DSDP/ODP localities that were not investigated in the original studies. All taxa considered as belonging in the recently erected genera are listed, and full synonymies cover all forms considered as belonging to the recently erected taxa. During the reinvestigation of samples from DSDP Hole 280A three new species were noted and are described herein. The new species are Dictyoprora nigriniae, Plannapus ? aitai (Artostrobiidae), and Lithomelissa ? sakaii (Plagoniidae).Problems with some age indicator taxa are discussed, namely the possible diachroneity of the last occurrence of Lychnocanium amphitrite, and the extent of the age overlap between Stichocorys delmontensis and Calocycletta (Calocyclopsis) serrata . A distinct biogeographic boundary to Radiolaria exists between the Mahurangi Limestone (Latest Eocene to earliest Miocene), and the Late Eocene t o Oligocene sections of the other South Pacific localities investigated. This necessitated the use of two different radiolarian zonal schemes for establishing the age ranges of the new taxa. The boundary seems to be attributable to differing latitudes o f deposition and associated water circulation patterns.
PANASENKO, E.S. AND RUDENKO, V.S., 2000. Possibility of breakdown of monotonic siliceous deposits using relationship of rock-forming microfossils (in example of Permian cherts in Sikhote-Alin. Geology of the Pacific Ocean, 15(1): 65-84. ABSTRACT: Supplementing the traditional biostratigraphic method for the breakdown of monotonic strata for siliceous deposits, a breakdown is proposed using the principal biotic events, manifested in generalized characteristics of taphocoenoses of siliceous microfossils. Such characteristics include the relationship of highrank taxons and evolution of the principal groups of radiolarians and siliceous sponges. On the basis of the dominant rock-forming groups of organisms it was possible to discriminate three lithological-facies varieties of cherts: sponge- and radiolariabearing, spumellaria-bearing and follicuculus-bearing. The discriminated strata were corrected using a zonal Permian scale f o r the Sikhote-Alin based on radiolarians and a magnetostratigraphic scale. The scale of the events, reflected in a change in the lithological-facies characteristics, is assessed. The proposed method is important for stratigraphy considering the poor preservation of microfauna, when species and even genera determination are impossible.
O’CONNOR, B, 2001. Buryella (Radiolaria, Artostrobiidae) from DSDP site 208 and ODP site 1121, Micropaleontology, 47 (1), 1-22. ABSTRACT: The genus Buryella is very important in the southern high-latitude radiolarian biostratigraphy of the Early to Early Late Paleocene, with South Pacific radiolarian Zones RP3-5 being defined using members of tile genus. The buryellid taxa of DSDP Site 2 0 8 and ODP Site 1121 are documented and discussed, and a biostratigraphic problem associated with South Pacific radiolarian Zone RP5 is addressed and rectified. Additionally three new species of Buryella are described (B. helenae, B. petrushevskayae, and B. tridica), and the family Artostrobiidae, genus Buryella, and species B. foremanae are emended. A new taxon tentatively assigned t o Spongopyle is also erected (S. ? sanfilippoae).
PESSAGNO, E. A. JR., CANTU-CHAPA, A., HULL, D. M., KELLDORK, M., LONGORIA, J. F., MARTIN, C., MENG, X. Y., MONTGOMERY, H., FUCUGAUCHI, J. U., AND OGG. J . G. 1999. Stratigraphic evidence for northwest to southwest tectonic transport of Jurassic terranes in central Mexico and 32
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Bibliography - 2000-2001 upward scaling of nutrient-related ecological increased effectiveness of resource utilization.
the Carribean (Western Cuba). In : P. Mann (Editor) Carribean Basins, Sedimentary Basins of the World 4 : 123150.
processes
and
RENARD M., BAUDIN F., BULOT LG, COCCIONI R., DE WEVER P., DISNAR J-R., EMMANUEL L., GALBRUN B., GARDIN S., ISHIDA K., LAMBERT E. & MONOD O. 2000. Chimiostratigraphie et stratigraphie séquentielle des alternances marno-calcaires du Valanginien-Hauterivien du basin vocontien (SE France) RST, Paris, 2000.
PICARD, M.D., 2000. Visit to a spreading center. Journal o f Geoscience Education. 2000; 48(2): 222-228 ABSTRACT: During Late Jurassic time a belt of radiolarian-rich sediment was deposited over a large part of the Tethys seaway, extending from the present Alps and Apennines (then about 15°25°N) through Greece to Indonesia. These sediments were deposited penecontemporaneously with the early rifting of the Atlantic.
ROBERTSON, A.H.F. AND PICKETT, E.A., 2000. Palaeozoic-Early Tertiary Tethyan evolution of melanges, rift and passive margin units in the Karaburun Peninsula (western Turkey) and Chios Island (Greece). GeologicalSociety-Special-Publication. 173: 43-82.
PRELA, M., CHIARI, M. AND MARUCCI, M., 2000. Jurassic radiolarian biostratigraphy of the sedimentary cover of ophiolites in the Mirdita area, Albania: New data. Ofioliti, 25(1): 55-62.
ABSTRACT: Similar Palaeozoic-Lower Tertiary units in the northern Karaburun Peninsula (western Turkey) and the adjacent island o f Chios (Greece) provide insights into the tectonic evolution of the Tethyan Ocean near the junction between the Taurides/Anatolides and Hellenides. The northwest Karaburun Peninsula is dominated by a highly sheared melange (c. > 2 km thick) with SilurianCarboniferous blocks (up to hundreds of metres in size) of neritic and pelagic limestone, black ribbon chert, shale, extrusives and volcanogenic sediments. The blocks are set in a matrix o f siliciclastic turbidites, pelagic carbonates and channelized conglomerates. Northern Chios is similarly composed of melange (c. 3-4 km thick) with limestone blocks dated as SilurianCarboniferous, black ribbon chert, shale and volcanics within predominantly siliciclastic sediments, including local conglomerates. Both melanges are unconformably overlain by Lower Triassic basinal successions (with sheared basal contacts), including terrigenous clastics, pelagic carbonate, radiolarite, lava and volcanogenic sediments, interpreted as rift successions. In both areas, successions shallow upwards into extensive Mesozoic carbonate platform facies, similar to those widely developed in the Taurides and Hellenides. On the Karaburun Peninsula, deposition was punctuated by emergence and localized deltaic siliciclastic deposition in latest Triassic-earliest Jurassic time. The Karaburun carbonate platform later emerged, eroded, then subsided in Campanian-Maastrichtian time; it then collapsed in the Maastrichtian-earliest Tertiary and was overlain by another melange (Bornova Melange), with blocks of both local platform-derived and accreted Mesozoic oceanic lithologies, and was finally thrust imbricated during continental collision. On Chios, a Lower Jurassic carbonate platform succession is overthrust by an exotic Carboniferous-Lower Jurassic mixed shallow-water carbonate and siliciclastic unit. Most tectonic hypotheses for the melange are problematic. They include formation as Palaeozoic basinal 'olistostromes', as an ideal Late Palaeozoic subduction-accretion complex basin, as an Early Triassic rift, or as entirely tectonic melange. The melange are seen here as the end-product of a combination of Late Palaeozoic southward(?) subduction-accretion (culminating in trench-microcontinent collision?), Early Triassic rifting and latest Cretaceous-Early Tertiary subduction/collision. Regional comparisons suggest that initial melange formation took place in Late Carboniferous-Early Permian time. Subsequent Early Triassic rifting was associated with siliciclastic, calcareous and radiolarian deposition, and andesitic volcanism. The Triassic rift was overlain by a subsiding passive margin adjacent to a northerly Neotethyan oceanic basin from Middle Triassic-Late Cretaceous. This ocean closed in the Late Cretaceous-Early Tertiary, resulting in collapse of the passive margin, subduction-accretion and further melange formation in a foredeep. Continental collision resulted in further deformation of the Palaeozoic melange, thrust imbrication o f the Mesozoic platform and shearing at its base.
ABSTRACT: Radiolarian assemblages of Jurassic age were determined in six sections sampled of Kalur Cherts (siliceous sediments on the top of the Mirdita ophiolites) in the Mirdita area (Northern Albania). The studied sections are: Kalur, Lumthi, Bukemira, Stalosi, Simoni and Perlati i Eperm. The radiolarian assemblages indicate that the age of the bottom of the section ranges from late Bajocian-early Bathonian to late Bathonian-early Callovian. These ages are compared with those of other sections o f the Kalur Cherts in Northern Albania.
RACKI, G. AND CORDEY, F. 2000. Radiolarian palaeoecology and radiolarites: is the present the key to the past? Earth Science Reviews 52 : 83-120 ABSTRACT: Radiolarian productivity pulses and related radiolarite deposition are phenomena difficult to understand from an exclusively actualistic viewpoint. Evolutionary selection pressure among silica-secreting marine plankton, both radiolarians and diatoms, has led toward more economic usage of rapidly shrinking nutrient resources, including dissolved silica, of the photic zone in the late Cenozoic oceans, and, in particular, a substantial modification of oceanic cycle by the diatom explosive radiation. Even if there is a proved link between biomineralization and dissolved silica loading among the phytoplankton only, the relative independence of modern siliceous planktic biotas from the available silica pool reflects mainly their progressive physiological specialisation during evolutionary history. Oceanic chemistry and productivity, as well as patterns of circulation/upwelling have changed radically during the Phanerozoic. Radiolarites apparently represent an `anachronistic' facies, as exemplified by their longlived and ocean-wide distribution in palaeo-Pacific, and hitherto, highlighted actualistic models of localized intra-oceanic wind-driven upwelling loci are of largely questionable applicability. In addition t o plate drift, hypersiliceous domains and intervals are explainable mostly by a large-scale volcano¯hydrothermal activity during major plate-boundary reconfigurations, which, in many ways, favoured siliceous biotas acme, and their skeletal remains accumulation and preservation. Factors tied to rapid, voluminous submarine eruptions, such as thermal buoyant megaplumes and basin overturns, offer a viable alternative for traditional climatic/circulation scenarios in case of hypersiliceous high productivity events irrelevant t o greenhouse-to-icehouse climatic change. The evolving carbon and silica cycles were coupled through the greenhouse effect and enhanced chemical weathering. Volcano-hydrothermal and tectonic uplift events, related mostly to extensive rifting and/or accelerated oceanic spreading, were the endogenous driving force that created this perturbation of the exogenous system. The present biogeochemical cycle is representative only for the overall silicadepleted post-Eocene oceanic ecosystems, which broadly correlates with a major expansion of diatoms groups extremely efficient in silica removal, and closely linking the silica budget with phosphorus and nitrogen cycles. Thus, an orthodox uniformitarian approach t o biosiliceous sedimentation, based on a silica-starved vigorous ocean, is of limited significance when applied to the pre-Neogene settings, especially in the peculiar planktic habitats of epeiric seas, as well as during biotic crises marked by strong geotectonic overprint. The major turnovers in marine siliceous biota composition, in particular after the end-Permian radiolarite gap, may have been coupled with discernible changes in an increasing biological control on the long-term oceanic silica cycling (`punctuated equilibrium'). The evolutionary turnovers have induced a stepdown decrease of dissolved silica levels through the Phanerozoic, contemporaneously with the general secular trend o f
SANFILIPPO, A. AND BLOME, C. D. 2001. Biostratigraphic implications of mid-latitude Paleocene-Eocene radiolarian faunas from Hole 1051A, Ocean Drilling Program Leg 171B, Blake Nose, western North Atlantic. In Kroon, D., Norris, R. D. and Klaus, A. (eds.), Western North Atlantic Palaeogene and Cretaceous Palaeoceanography. Geological Society, London, Special Publication 183, pp. 185-224. ABSTRACT: Abundant well preserved radiolarians were recovered from Ocean Drilling Program Leg 171B Hole 1051A, western North Atlantic, and range from upper middle Eocene radiolarian Zone RP16 through lower Paleocene Zone RP6. This mid-latitude fauna contrasts with tropical faunas in lacking many tropical zonal markers and in its high proportion of diachronous first and last
33
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Bibliography - 2000-2001
occurrences. Hole 1051A contains the early Eocene/middle Eocene and Paleocene/Eocene (P/E) boundaries, and the only known record of a well preserved Late Paleocene Thermal Maximum (LPTM) radiolarian assemblage. There is no gross change observed in the composition of the fauna, only a minor increase in the number o f first and last occurrences across the LPTM interval and P/E boundary. Calcareous evidence indicates two hiatuses, each 1 - 2 m.y. long, one in the lowermost middle Eocene and a second in the upper Paleocene. Presence of the middle Eocene hiatus i s corroborated by an abnormally large radiolarian turnover. Twentysix events are documented and show that most of radiolarian Zone RP10 and a substantial part of Zone RP9 are missing. Seven new species are described: Spongatractus klausi, Calocyclas aphradia, Lychnocanoma (?) parma, Sethocyrtis austellus, Sethocyrtis chrysallis, Thyrsocyrtis (Pentalacorys) krooni and Thyrsocyrtis (Thyrsocyrtis) norrisi .
embedded in the Triassic Wang Yai Siltstone. This fauna includes Entactinia variospina, Archocyrtium lagabriellei, Pylentonema rachebeufi, and Astroentactinia multispinosa, which characterize the Tournaisian (Early Carboniferous) radiolarian fauna o f northwestern Europe. The Early Triassic radiolairan fauna is present in siliceous shale that crops out in a Highway 42 road cut near Wang Yai. This fauna contains Parentactinia nakatsugawaensis and P. okuchichibuensis, which are also present in the Spathian (late Early Triassic) Parentactinia nakatsugawaensis Assemblage in bedded chert sequences of Japan and northern Thailand. The Middle Triassic radiolarian fauna is present in bedded chert sequences exposed in an active quarry near Chana. Although fossil preservation is poor, these beds evidently contain the late Anisian or early Ladinian radiolarian fauna that has been reported from European Tethys, Japan, and the Russian Far East. Two new species are described: Polyfistula? grantmackiei and Tetrarhopalus? sabayoiensis. The closure of Paleotethys is confirmed as having occurred during the Late Triassic, based on a newly obtained Middle Triassic radiolarian fauna from southern Thailand, and on recent lithostratigraphic, biostratigraphic, and tectonostratigraphic studies in Southeast Asia.
SASHIDA, K., IGO, H., ADACHI, S., UENO, K., KAJIWARA, Y., NAKORNSRI, N. AND SARDSUD, A., 2000. Late Permian to Middle Triassic radiolarian faunas from Northern Thailand. Journal of Paleontology, 74(5): 789-811.
SCHIEBER, J., KRINSLEY, D. AND RICIPUTI, L., 2000. Diagenetic origin quartz silt in mudstones and implications for silica cycling. Nature, 406(6799): 981-985.
ABSTRACT: Moderately well-preserved Late Permian to Middle Triassic radiolarians are identified in chert beds that occur in the Shan-Thai Block of northern Thailand. These radiolarians are identical to the faunas of the Late Permian Neoalbaillella ornithoformis and N. optima Assemblage Zones and the Triassic Parentactinia nakatsugawaensis and Triassocampe coronata Assemblage Zones reported in chert sequences of Japan. We discovered the radiolarian faunas, apparently indicating Late Permian and Early Triassic ages, in almost continuous sequences o f chert and shale exposed in the north of Chiang Mai. The occurrence of these radiolarian faunas provides important data to solve the P/T (Permian/Triassic) boundary in pelagic sequences. Our present discovery also furnishes significant data to reconstruct the paleobiogeography of Mainland Thailand during Late Permian t o Middle Triassic times. Fifty species belonging to 35 genera, including three unidentified genera, are investigated taxonomically. Four new species Pseudospongoprunum? chiangdaoensis, Cenosphaera igoi, Cenosphaera? rugosa, and Tlecerina? apsornae are described.
ABSTRACT: Mudstone - the most abundant sedimentary rock type, composed primarily of clay- or silt-sized particles - contains most of the quartz found in sedimentary rocks. These quartz grains, which are chemically and mechanically resistant and therefore preserve their characteristics well, have long been considered to be derived from the continental crust. Here we analyse quartz silt from black shales in the eastern USA, dating back to the Late Devonian period (about 370 million years ago), using backscattered electron and cathodoluminescence imaging and measure oxygen isotopes with an ion probe. Our results indicate that up to 100% of the quartz silt in our samples does not originate from the continental crust. Instead, it appears to have precipitated early in diagenesis in algal cysts and other pore spaced, with silica derived from the dissolution of opaline skeletons of planktonic organisms, such as radiolaria and diatoms. Transformation of early diatoms into in situ quartz silt might explain the time gap between the earliest fossil occurrences of diatoms about 120 Myr ago and molecular evidence for a much earlier appearance between 266 or even 500 Myr ago. Moreover, if many other mudstone successions show similarly high proportions of in situ precipitated - rather than detrital - quartz silt, the sedimentary record in mudstones may have been misinterpreted in the past, with consequences for our estimates of palaeoproductivity as well as our perceptions of the dynamics and magnitude of global biogeochemical cycling of silica.
SASHIDA, K., SALYAPONGSE, S., AND NAKORNSRI, N. 2000. Latest Permian radiolarian fauna from Klaeng, eastern Thailand. Micropaleontology 46 (3) : 245-263. ABSTRACT: A latest Permian radiolarian fauna is described from a chert-clastic sequence exposed at Khao Wang Chik, Klaeng, eastern Thailand. This fauna was recovered from a continuous siliceous sequence comprised of white to light gray siliceous shale, dark gray bedded chert, and dark gray siliceous shale. The fauna is composed of Neoalbaillella optima, Albaillella levis, A. triangularis, Entactinia itsukaichiensis, Triaenosphaera minuta, Ishigaum trifustis, Nazarovella inflata, Triplanospongos musashiensis, Copicyntra akikawaensis and others. These radiolarians represent the latest Permian Neoalbaillella optima Assemblage reported from Japan, Russian Far East, Philippines, south and southwestern China, and northern Thailand. The radiolarian-bearing sequence was probably deposited in the deep, pelagic environment of the Paleotethys Ocean. An overlying coarse-grained elastic sequence reflects an abrupt change in local depositional environment, possibly caused by the narrowing of the Paleotethys Ocean in Early Triassic time. Twenty-eight radiolarian species belonging to 15 genera are systematically investigated. One new genus, Klaengspongus, and four new species, Triaenosphaera longispina, Ishigaum klaengensis, Pseudospongoprunum? fontainei , and Klaengspongus spinosus are described.
SHIMIZU, H., KUNIMARU, T., YONEDA, S. AND ADACHI, M., 2001. Source and depositional environments of some Permian and Triassic cherts; significance of Rb-Sr and SmNd isotopic and REE abundance data. Journal of Geology, 109(1): 105-125. ABSTRACT: Rb-Sr and Sm-Nd isotopic data, rare earth element (REE) abundances, and major-element compositions are reported f o r the Triassic cherts of the Mino Terrane in the Inner Zone o f southwest Japan and for the Permian and Triassic cherts of the Sambosan Terrane in the Outer Zone of southwest Japan. Rb-Sr isotopic data of the Mino and Sambosan cherts define separate isochron lines, and the Rb-Sr ages of ca. 210 and 240 Ma reflect the chert deposition and the end of the subsequent chemical diagenesis during which amorphous silica was transformed into quartz. It is concluded that the Rb-Sr isotopic system of the cherts becomes essentially homogenized among biogenic silica, detrital components and hydrogeneous components during deposition, and the subsequent chemical diagenesis before lithification due to high mobility of Rb and Sr. The Sr initial ratio (0.71363) of the Triassic Mino cherts is clearly higher than those (0.7079 and 0.7068) o f the Triassic and Permian Sambosan cherts, which are close to the estimated oceanic Sr ratios of 0.7066-0.7081 in the Permian and Triassic. On the other hand, Sm-Nd isotopic data do not define isochron lines. This might be due to incomplete homogenization o f the system among biogenic silica, detrital components and hydrogeneous components during deposition, and chemical diagenesis because of low mobility of REE. Initial Sr and Nd isotopic ratios of the Mino cherts can be interpreted by mixing typical continental crustal rocks, represented by aeolian loess compositions, with a small amount of Precambrian rocks (
