Kopylów anomaly - new magnetic data in the south-east part of Poland Olga Polechoñska e-mail:
[email protected] Polish Geological Institute Rakowiecka 4 Str., 00-975 Warsaw, Poland
Irena Kosobudzka e-mail:
[email protected] Geophysical Exploration Company Jagielloñska 76 Str., 03-301 Warsaw, Poland
From many years a lot of magnetic surface measurements have been executed in order to supplement the database and create a new Magnetic Map of Poland. In the end of these year, northern part of it (scale 1:500 000) will be published. The southern part will be constructed as the dataset is complement by measurements from Carpathian and Sudetes. Map of magnetic anomaly DZ
The margin zone of East European Craton was under research of Polish Geological Institute and Geophysical Exploration Company since 1998 to 2002 (Kosobudzka I., 2002). Approximately 120 thousand data points were collected with 2 pts/km2 average surface density. In comparison with “Magnetic map of Poland” (Karaczun K. et al., 1978) which is obligatory till today, more detailed features and some new anomalies were occurred.
1A
Map of magnetic anomaly DT A
The “Map…” (Karaczun K., 1978) was interpolated on database of vertical component of magnetic i n t e n s i t y D Z measurements. An exemplary part of it is presented on fig.1A. Fig.1B shows magnetic map of the same area but constructed on base of new data (total intensity DT). To emphasize differences between both figures, the same colour scale and increment was used.
1B B’
A’
The area of research is characterised by strong block tectonics, with shallow crystal basement (from1,2km on NE to 2,2km on SW). The main faults: W³odzimierski, Udal and Œwiêcice and stratigraphic boundaries (by Dembowski & Porzycki, 1988) are presented on fig.2. lt fau
2
A
ica iêc Œw Cw Cw
REJOWIEC ANTICLINE
Ud al fau lt
CV CV CNA CNB
CNB
CNC-CwA
CNA
B’ A’
CNC-CwA
B lt fau
i sk ier zim lod W Cw
CNC-CwA
Main tectonic units and structures: CW - Lublin Beds and younger Westphalian, CNC- CWA - Kumów Beds, CNB - Bug Beds CNA - Komarów Beds, CV - Lower Carboniferous - faults
- boundaries of Carboniferous
B
More details can be seen on gravity map (fig.3). The second derivative of Bouguer anomaly with 1km upward continuation accentuates not only tectonic elements but separate layers too (e.g. CV near the east border). It's strongly industrial area covered with dense net of few hundred meters wells and numerous seismic lines. Blue lines on fig.2 show location of two of them which crosses above anomaly of further interest.
3 Chelm
Krasnystaw
Wladymir
Hrubieszow
Zamosc
Second vertical derivative of Bouguer anomaly with 1km upward continuation shaded relief map, light from north-east; black lines indicates the same tectonic and stratigrafic situation as on fig 2.
The attention should be paid to two “new” anomalies appearing on fig.1B. Minor, oblong anomaly is strongly connected with Udal fault and caused by depression of crystal basement top (fig.4). It constraints from north-west an uplifted block. Second anomaly - Kopylów is located at the east edge of that block. This positive, oval anomaly, in contrast with the previous one, can't A’ B Geological interpretation of seismic lines crossing over be explained, only by depth diversification of crystal basement Kopylów anomaly (based on Wnuk Z., Œwierczewska top. As it is seen on fig.4 anomaly spreads over fault which goes J., 1997) DT along AA’profile B’ from crystal basement up to Carboniferous sediments. This fault DT along BB’ profile could be the channel for a certain volcanic intrusion from basement A to younger strata. But this is the question for further investigations.
4
400
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0
NE
-200
SE
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References: • Dembowski Z., Porzycki J., 1988: „Carboniferous of the Lublin Coal Basin” Prace Instytutu Geologicznego CXXII, Wydawnictwa Geologiczne, Warszawa, p...156; • Karaczun K., Karaczun M., Biliñska M., Uhrynowski A., 1978: „Mapa magnetyczna Polski. Anomalie sk³adowej pionowej „Z” pola magnetycznego Ziemi”, Wydawnictwa Geologiczne, Warszawa • Kosobudzka I., 2002: “Pó³szczegó³owa mapa magnetyczna T w brze¿nej strefie platformy prekambryjskiej 1998-2002 r.” doc. PBG • Wnuk Z., Œwierczewska J., 1997: „Opracowanie badañ sejsmicznych, temat: KrasnystawHrubieszów-Tyszowce” doc. PGNiG S.A. Geofizyka Toruñ.
NW
1km 1km
K
J3
CH1
CE1
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D2
m1 m2 C D1 C
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