Chapter 1. INTRODUCTION

Chapter 1. INTRODUCTION 1.1 General Iron is one of the most indispensable metal to man and all the modern industry is dependent on its supply and availability. In modern times, this heavy industry is rightly considered as an index of nation’s prosperity, the relative economic strength and might of a country is reflected in the possession of large and integrated iron and steel works, which is also a measure of the political power and prestige which that country enjoys. The two important ore minerals of iron are magnetite and hematite. Magnetite is also known as magnetic iron ore because it is easily attracted by a magnet. It is a heavy black mineral with metallic luster. Hematite which is the ore mineral most favored for iron smelting purposes in modern times is a steel-gray to iron- black colored mineral which is as hard as magnetite (hardness=5.5 to 6.5) but slightly less heavy (usually specific gravity varies from 5.0 to 5.3). It has also a metallic luster. It rarely occurs in nature as the native metal. NMDC Ltd is a public limited company incorporated under the Ministry of Steel, Government of India in the year 1958 with the mandate to explore and develop minerals to produce raw materials for the industry. It has grown to the status of the single largest producer of iron ore products in India with supplies to both domestic and overseas customers. It has developed a sophisticated Research & Development Centre at Hyderabad to carry out technology development missions in mineral processing, flow sheet development, mineralogical studies and product development. Geologists have been using aerial photography to help their exploration efforts for decades. Since the advent of satellite imagery with the launch of the first earth resources satellite (Landsat 1) in 1972, exploration geologists are increasingly involved in interpreting digital images (computerized data) of the terrain. Recent technological advances now provide high resolution multispectral satellite and airborne digital data. More recently, geologists involved in research and commercial exploration have been seeking out the more elusive potential mineral deposits, e.g. those hidden by vegetation or by Quaternary cover. Usually geochemical, geophysical and other map data are available. The multispectral remotely sensing datasets that have been used in this research are comprised of the LANDSAT Enhanced Thematic Mapping (ETM+) of P/R = 142/47.

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1.2 Location of the study area: "Bailadila" range of hills derives its name from the shape of hills. As the hills of the range look like 'the hump of an ox' it's named so by the native inhabitants of this place. Bailadila ranges of hills are located 40kms South-West of Dantewada, Chhattisgarh. The area lies between latitude 18⁰35’48” and 18⁰38’30” N and longitude 81⁰13’22” and 81⁰16’00” E within the survey of India toposheet No. 65F/1, F/2,F/5 & F/6.

1.3 Physiography of the area: Generally, the area is mountainous, comprising massif plateaus with some surrounding plains that drop gradually from an altitude of 1276mts to 400mts. The highest massif in the area is 1276mts above mean sea level. The topographic sheets 65-F-1 and 65-F-2 of GSI cover the main area of mine at a scale of 1:50,000 at which we work. 1.4 Previous work:The area had received less attention in terms of geological research in the past. However, some projects have been carried out, most of which aim at the appraisal of surface and groundwater resources for agricultural development. Among the researchers: 1934-35, Crookshank and P.K.Ghosh of GSI mapped the entire range geologically on 1” = 1 mile scale for the first time.  Crookshank’s publications (1938 & 1961) still remain as valuable documents on the geology of the area.  Crookshank (1938) divided the iron ore occurrences of Bailadila range into fourteen distinct deposits numbering 1 to 14. GSI produced valuable geological maps, including many theory bulletins on that area but due to higher sensitiveness of Naksalism in Dantewada it’s been always a tough task to find out stratigraphy with high resolution. Thanks to satellite imagery that provide study and interpretation of that area on which we took some information. The area has been covered by airborne magnetic and radiometric surveys, in addition to ground geophysics, comprising spontaneous potential, magnetic, electromagnetic, electrical resistivity, and radiometry measurements. The area has also been mapped geochemically at some locations of interest.

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Fig. 2

Fig. 1

Fig.5

Fig. 3

Fig. 4 3

1.5 Objectives of the present studies:The aim of this study is to use remote sensing for Iron exploration and mined area in the Bailadila Hill Ranges by establishing a relationship between known Iron ore deposits along the structural features and lineaments with un-mined locations. Remote sensing images have been widely and successfully used for mineral exploration for decades. Although iron can’t be detected directly by any remote sensing method, the presence of minerals such as iron oxides and other structural features help us to coordinate the deposit’s confirmation. Iron found to occur with Igneous, Basic- Ultrabasic rocks. Magnetite occur abundantly and widely spread as missive, granular and laminated deposits formed by magmatic segregation, injection, contact metasomatism or associated with skarn deposits and black sands in placers deposits so mostly they are of magmatic formation with high Ti-Fe. In crystalline metamorphic rocks occurs as large bed and lenses. Sedimentary deposits are of chemical origin.

1.6 Geographic Disposition:"Bailadila" range of hills derives its name from the shape of hills. As the hills of the range look like 'the hump of an ox' it's named so by the native inhabitants of this place. Bailadila ranges of hills are located 40kms south west of Dantewada, Chhattisgarh. The area lies between latitude 18⁰35’48” and 18⁰38’30” N and longitude 81⁰13’22” and 81⁰16’00” E within the survey of India toposheet No. 65F/1, F/2, F/5 & F/6. The area is easily accessible from Raipur (425 kms), Vizag (470 kms) and Hyderabad (560 kms). There is a rail route, known as KK line from Vizag, running through the foothills of Bailadila – 14,11B & 11C. Bailadila enjoys a mild weather, 40⁰C in summer and 10⁰C in winter. The region experience heavy rain from June to October, with 350 cm in Hills and 250 cms in the foothills, with thick fog.

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Chapter2. Geological Setting:2.1 Regional Geology:It is a very rich deposit of iron ore (Hematite) in these ranges, with an estimated reserve of 1200 mil. tonnes. This iron ore series is of Precambrian age and is almost similar in nature to the other series of Bihar, Orissa, Karnataka etc. the series essentially consists of Iron ore, BHQ, chert, shale, tuff, and quartzite. Metabasalt traps with tuffs and cherts intervene between a suites of older metamorphics grouped into Bengpal series by Crook Shank. Initial works in this region was started by P.N. Bose (GSI, 1899), who first reported Iron ore in Bailadila. In 1934-35 Dr. Crook Shank and Dr. PK Ghosh of GSI mapped the area in 1”=1mile. Crookshank (1938, 1961) divided the range into fourteen deposits, numbering 1 to 14. Heron (1946) gave an estimated reserve of 3036mt. P. K. Ghosh et.al. (1961-63) mapped the area in 1”=1 foot and gave an estimated reserve of 1135 mts. Dr.Chatterjee (1964-65) gave the details of mineralogy and mode of formation. Sarkar dated this orogeny between 2000-2500my.Recently Iyengar and Banerjee (1972) considered the Bailadila range to be older than Bonai, Hospet and Goa range. Bandhopadhyay reviewed the stratigraphic disposition in 1977. The regional strike in the main Bailadila range is N- S accepting the Southern ridge with steep Easterly dip and swerving in either side. Crookshank identified the two ridges as two folded overturned syncline and an anticline occupying the valley in between. The Deposit 13 &14 suggests a closure, but is highly disturbed by superimposed deformations. Two set of younger folds Easterly and North Westerly superimpose the earlier structures. The iron ore has generated by leaching of silica from banded hematite quartzite (BHQ) and enrichment by further deposition of iron oxide by meteoric water. Often shale has been partially replaced by iron oxide. This replacement and enrichment was greatly controlled by structure, grain size and texture of parent rocks. Massive ore has resulted from the fractured rocks and the bedded rocks has mainly transformed into laminated ore.

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The regional stratigraphic sequence as established by earlier workers: Table: 1 Dolerites Pegmatites Charnockites Intrusive Igneous rocks Granites Greenstone & Amphibolite Intrusive ----------------------------------------Unconformity------------------------------------------Banded hematite quartzite and shale with associated iron ore deposits Bailadila Iron Ore Series Grunerite quartzite Ferrugenious phyllite etc. White quartzite ----------------------------------------Unconformity----------------------------------------Bengpal series Covered in survey of India Topo Sheet No. 65 F/1, 2, 5, 6.  Latitude: 18o 35’ ----- 18o 54’ 30” (E)  Longitude: - 81o 10’ 30” ---- 81o 15’ 30” (N) 1. Invented by P. N. BOSE --- 1899 2. Worked in detail by H. Crook Shank--- 1932 3. Age Precambrian ---- 2090 My. Years 2.2 GENERAL GEOLOGY:Iron Ores BHQ Shale / Phyllites / Quartzite Unconformity Basic Rock, Tuffs Schists (Qtz-Sericite) Origin: - By Khodyush (1969) NOTE-Banding indicates climatic changes from warm humid to dry cold period.

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1. The oxidizing environment and increase in Ph (Alkalinity) was resulted due to flourishing organic life in seawater during warm humid period. Intensive oxygen content of seawater resulted in oxidation of Iron bi-carbonate Fe2 (Co3)2 and iron precipitated in form of Iron hydroxides. 2. Cold dry period resulted decrease in organic activities and oxygen contents of seawater hence acidity increased during which greater amount of silica precipitated and Fe++ was suppressed.

o The thickness of banding in B.H.Q resulted from seasonal variation of physico- chemical changes caused by episodic supply of organic material during annual cycle. Microfoldings are due to geotectonic disturbances. o Enrichment of Iron ore from BHQ is by the process of leaching and enrichment both by meteoric waters and hydrothermal solutions. o Steel gray ore occurs commonly in core of synclines due to thermodynamic forces resulted from geo-tectonic disturbances. Blue dust is formed due to removal of cementing material due to meteoric water or due to submergence in saturated water zones from semi - pervious (Mass. Blue, Powdery) type of ore or laminated ores. 2.3 Structure:Bailadila hills form two parallel ranges running along approx. N-S directions, steeply dipping towards East. This range is 40 Kms. Long and 4.00 Kms wide. The highest point is 1276 Mts above sea level at Dep10. These ranges formed two isoclinal synclines and an anticline presently existing as gallinala valley. These folds plunge in north near Jhirka and opens in south near Loha Village. The ranges are intersected by numerous faults and folds.

2.4 Genesis of the Deposits:The origin of these ores is of Khodyus. The banding indicates climatic changes from humid to dry period. The oxidizing environment and increase in Ph resulted due to flourishing organic life in sea water during warm humid period. Intensive oxygen content

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of sea water resulted oxidation of iron bicarbonates and iron precipitated in the form of iron hydroxides. Cold dry period resulted decrease in organic activities and oxygen contents of sea water hence acidity increased during which greater amount of silica precipitated and iron got suppressed. The thickness of banding in BHQ resulted from seasonal variation of physico-chemical changes caused by episodic supply of organic materials during annual cycle. The geotectonic disturbances caused micro folding. The enrichment of iron ores from BHQ is by the process of leaching, by meteoric water and hydrothermal solution. Steel grey ore occurs commonly in core of synclines due to thermodynamic forces resulted from geotectonic disturbances. Blue dust is formed by removal of cementing material by meteoric water or due to submergence of saturated water zones. Following lithosequence from granitic boundary in the East was established,

Thin soil cover and Laterite, Iron ore Iron formation Banded Iron formation Ferruginous shale White Quartzite

2.5 Brief lithological descriptions:White Quartzite: Underlies the ferruginous shales in patches near the foothills. Ferruginous shale: These are soft and earthy, varying from buff to cherry red in color. These are loose to very compact at places. They underlie the iron formation and overlie the White Quartzite. Intercalated shale bands were encountered in some of the deposits. Iron formation: BHQ exposure is prominent in the Eastern flank. The tongue shaped extension of BHQ is exposed on the surface between CS13 to CS15. Iron Ore: Ore concentrates mostly towards E &NE part of CAL comprising outcrops of Steel Grey Hematite and Laminated ore underlain by flaky ore/Blue Dust which in turn overlies ferrugenious shale and BHQ. Hematite is weathered to Laterite, Goethite and Limonite on the slopes. Laterite and Soil Cover: Hematite has been weathered to Laterite and Goethite with limonite in the slopes and saddles. Layers of hydrous iron oxide and ochers are present.

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2.6 General description of the deposits:2.6.1 Deposit-5:Deposit 5 is the southernmost deposit in the western ridge of Bailadila range. The deposit has a strike length of 3500mts and its width varies from 100 to 400mts. The Western side of the mine is marked by a cliff due to faulting which goes almost vertically down for about 300 mts. The ore strikes N 370 and has a dip varying from 45-600 towards East. The South block extends for 1 Km, Central and North West blocks have a length of 1 Km, and the North block occupies the rest of the area. The area was studied in 35 geological cross sections. 2.6.2 Deposit-10 & 11A:Deposit 10 is located in the middle of the Eastern limb of the folded mountain range. Towards North it is separated from Deposit 8 and towards south from Deposit 11A. Towards East deposit slopes down to Bacheli plain and west to Galli valley. The general trend of the ridge is N-S and easterly dipping. The ore body has a length of 2600 mts and an average width of 400-500 mts. It has been divided into two blocks – North (CS 1 - 9) and South (CS 9 - 16), on the basis of ore characteristics. Deposit 11A occurs immediately to the North of D11B on the Eastern ridge of Bailadila range. It is bounded by Deposit 11B in the south and Deposit 10 in the North. The ore body extends North –South for a strike length of 2500 mts. The ore body is divided into two parts North blocks (CS 0 - 11) and South blocks (CS 11 - 25). Ore in the North block is pocket and not suitable for mechanized mining, and the width of the ore body in the South block is 50-250 mts. 2.6.3 Deposit 11C:Dep 11C forms the Southernmost deposit on the Eastern limb of the Bailadila Range and is marked by high grade iron ore capping between Kodenar valley and Jhuvampass. It lies between the latitude 18°38’32” - 18°37’16”N and longitudes 81°14’30” to 81°13’55”E, covered by Survey of India toposheet 65F/2. It extends over 2300 mts with width varying from 125mts (CS5) to 750mts (CS10). Ore occurs between 1213 to 950mts level. Towards North of it lies Dep 11B and towards South lies Dep14. Towards East it steeply slopes down to granitic plains of Kirandul and towards west to Galli valley. Ridges generally trends in NNW-SSE direction with dip varying from 45⁰ to sub vertical. The ridge of 11C forms a syncline with axis trending N15⁰E. Three set of faults (EW, NNW-SSE in the North, NW-SE in the South) have dissected the deposit. In the initial phase of exploration bore holes were drilled by IBM(760mts) and NMDC(2456mts),based on which 19 cross-sections were prepared and reserve estimation

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was done upto a level of 970mts. In the initial phase of exploration bore holes were drilled by IBM (760mts) and NMDC (2456mts),based on which 19 cross-sections were prepared and reserve estimation was done upto a level of 970mts. 2.6.3.1 Structures: The general trend of the deposit varies from N15°E –S15°W to N30°W – S30°E and dip Easterly from 45° sub vertical and vertical. The ridge of 11C forms a syncline with the axis approximately trending N15°E. This has been affected by later folding almost across the regional fold pattern with its axis plunging easterly. This has resulted in swerving of the regional strike. The NW-SE trending fold was superposed on this but has weak signatures. The ore body is dissected by mainly three sets of faults striking EW in the area around CS5, NNW-SSE in the North and NW-SE in the Southern portion of the deposit. Lineations like slickensides and minor fold axis are present. Three set of joints are present NNW-SSE, WSW-ENE and NNE-SSW.

2.6.3.2 Ore types:The ores of 11C deposit have been classified on the basis of physical, chemical characteristics and association as follows: Type-1 Type-2 Type-3 Type-4 Type-5

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Steel grey hematite Blue hematite Laminated Hematite Lateritic/Limonitic Ore Blue dust/Flaky ore

2.6.4 Deposit 14:Deposit 14 the first mechanized iron ore mining project of NMDC was started in 1968, with a handling capacity of 5.5 million tonnes of ore per annum following a long term agreement for the iron ore export to Japan. The ore body of Deposit 14 has a strike length of 1500mts. and width of 1300 to 100mts. The general orientation of the ore body is NNW-SSE having steep to Easterly dip. Deposit 14 has two distinct ore zones, i.e. hard-ore zone and blue dust zone. The hard-ore zone occurs between 1089mrl to 1005mrl in the western flank and the blue dust zone

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from 1089mrl to 1179mrl in the Eastern flank. The topmost RL of the hill range is 1196 m whereas, the top bench RL is at 1179m. the mine working was initially confined upto 1029MB considering the market of hard ore, however the ultimate pit bottom has been planned upto 1005MB.Chemical and physical characteristics and classification of the ore types in D14 are almost similar to D11C. 2.7 Quality and Quantity of Products: The quality and quantity of the iron ore produced in the Kirandul Complex is as follows Table: 2 Sizes and Grade of Products Elements Fe% SiO2% Al2O3% P% LOI

Baila ROM (150+10mm) 66.6 1.1 1.20 0.05 01.8

Baila Fines (-10mm) 65.2 2.11 2.0 0.03 03.00

Baila Lump (-40 + 6.3mm) 66.81 01.26 1.1 0.036 1.48

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Chapter 3:- Methodologies 3.1 Quality Control and Mining

Table: 3

3.1.1 Stages of investigation prior to mining:• Exploration: Contour and geological mapping to demarcate the mineral bearing areas. • Prospecting: Includes pitting and trenching, driving adits and core drilling. • Proving: Detailed investigation prove the ore in three dimensions for computation of reserves.

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•

Development preliminary to mining: Carrying out lump recovery tests, mapping of exposed bench faces, analysis of blast hole sludge etc.

3.1.2 Different aspects of Mining: Mining has been started from top by slicing method i.e., formation of benches. Waste and ore are removed by excavator (shovel) and dumper combination. Average heights of the benches are maintained (12m) as per the Regulations and permissions granted by DGMS. Drilling operation is carried out with the help of blast hole drills & holes of 250/150 mm diameter are drilled. Dust extractors for dust collection and water injection system for wet drilling are provided in the drills. After the drill holes are completed in a block, explosives are charged and the strata is blasted taking all the safety precautions. Crawler drill is used for secondary drilling, if required blasted material is dozed for deployment of shovels for loading into the dumper for transport of ore. To plant and waste to waste dump. Wherever softer strata not requiring blasting are encountered, the same is excavated by the shovel. Waste rock is mined & piled up at the surface in the waste dump, near the edge of the mine. It is also tiered and stepped, to minimize degradation. 50/85/100T Dumpers are being used for haulage of ore/waste to crusher/waste dump respectively. Proper drainage for the road is also maintained. All the provisions and code of practices for open cast mining stipulated by DGMS are followed. Water sprinkling on the haul road is done for dust suppression regularly.

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Images of rocks contain Iron Ore in Field of Bailadila Iron Ore Mine Specific Gravity: - 4.70 Fe%- 69.0 Gravity:- 4.70 Fe%- 69.0

STEEL GREY HEMATITE

Type – 1

Fig. 6

Steel grey Hematite, dep.-14, 1053 MB

Massive compact hard, sharp edged steel grey hematite. Joint planes frequent.

Specific Gravity:- 4.30 Fe%- 67.50

BLUE HEMATITE Type – 2 Blue Hematite, dep.-11C, 1078 MB Massive compact hard curved edged blue hematite blasted sized ore.

Fig. 7

14

Specific Gravity:- 4.20

Fe%- 68.0

BLUE/ BLUE GREY HEMATITE

Type – 2

Blue / Blue grey Hematite, dep.-14, 1065 MB

Fig. 8

Massive compact hard curved edged blue hematite.

BLUE / BLUE GREY HEMATITE Type – 2

Blue / Blue grey Hematite, dep.-14, 1065 MB

Massive compact moderately hard curved edged blue hematite.

Fig. 9

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Specific Gravity:- 4.00 Fe%- 67.0

COMPACT, MODERATELY SOFT, LAMINATED HEMATITE

Type – 3

Compact, Moderately soft, Laminated Hematite, dep.-14, 1113 MB

Fig. 10

Specific Gravity: - 3.80 Fe%- 64.0

COMPACT AND HARD LAMINATED HEMATITE

Type – 3

Compact and Hard Laminated Hematite, dep.-11C, 1090 MB

Fig. 11

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Specific Gravity:-3.50 Fe%- 61.0

Lateritic limonitic ore

Type-4: Lateritic limonitic ore, dep.-14, 1157 MB

Fig. 12

Rounded boulder shows nodular appearance.

SpecificGravity: 3.30 Fe%- 67.0

BLUE DUST Type-5: Blue dust, dep.-11C, 1054 MB

Fig. 13

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BANDED HEMATITE QUARTZITE Fig. 14

Type-6: Banded Hematite Quartzite Specific Gravity: - 3.00 Fe%- 49.6

Waste Zone: Yellow Ochre Patch

Waste Zone: Occurrence of Yellow Ochre patch in blue dust. 11C, 1102 MB

Fig. 15

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WASTE ZONE YELLOW OCHRE

WASTE ZONE YELLOW OCHRE, DEP-11C, 1114 MB

Fig. 16

Specific Gravity: 2.70 Fe%- 25.0

WASTE ZONE: SHALE TYPE-7: WASTE ZONE: SHALE, DEP.-14, 1167 MB

Fig. 17

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WASTE ZONE: GREEN SHALE Fig. 18

TYPE-7: WASTE ZONE: GREEN SHALE; DEP.-14, 1153 MB


WASTE ZONE: WHITE CLAY IN BLUE DUST

Type-7: Waste ZONE: white clay IN BLUE DUST; DEP.-14, 1101 MB Fig.19

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3.2 Remote Sensing and Software:Remote sensing is the collection of information about an object or area without being in physical contact with it. Data gathering systems used in remote sensing are: 1. Photographs obtained from manned space flights or airborne cameras, and 2. Electronic scanners or sensors such as multispectral scanners in satellites or aeroplanes and TV cameras, all of which record data digitally. A geographic information system (GIS) uses computers and software to leverage the fundamental principle of geography—that location is important in people’s lives. GIS takes the numbers and words from the rows and columns in databases and spreadsheets and puts them on a map. It allows us to view, understand, question, interpret, and visualize our data in ways simply not possible in the rows and columns of a spreadsheet. And with data on a map, we can ask more questions. We can ask where, why, and how, all with the location information on hand. We can make better decisions with the knowledge that geography and spatial analysis are included. •

The geospatial database is core of the GIS system and enough care must be taken in designing database

•

Analysis techniques, which are applied to spatial data are often very different to those applied to non-spatial data.

•

GIS include tools for the exploration, analysis and summarizing of spatial data.

A GIS combines layers of information about a place. What layers of information to be combined depends on the purpose. •

Basic data sets for GIS:- 2 Types  (1) Spatial data  (2 ) Aspatial data

1. Spatial Data:  Gives information about the features geometrical orientation, shape, size and relative position with respect to other features.  Described by x, y coordinates.

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2. Aspatial or Descriptive data:  Qualifies information about various attributes like area, length, number, name, characteristics of features.  Best organized in alphanumeric fields.

I

A

2

75

II

B

23

34

III

C

3

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3.2.1 Advantage of Digital Data: Implementation of Analysis Models.  Choice of different map projections.  Choice of different map designs and layout.  Better visualization techniques and representation.  Enables a non-cartographer to produce maps.  Perfect registration between different layers of maps / different thematic maps.  Updation becomes easy and consistent by setting certain rules and by developing algorithms.  No scale associated with digital data.

3.3 Data for ArcView-GIS 3.1:We get the scanned map of toposheet no. 65-F-1 and 65-F-2 and crop out the required are as in fig () in which hills with affected lineaments in which ore deposits present. We start to prepare themes as different required layers like stream layer, contour layer theme and lineament layer theme, which provide digital data for mapping and interpretation for further studies.

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Step1. Crop out the required area from the mosaic toposheets.

Fig. 21

Fig. 20

Step2- Add up the Data in Arc- GIS 3.1

Fig. 22 Fig. 23

Step3- Apply Georeferencing to the built theme with 8 points of particular latitude and longitude and warp them with present toposheet.

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3.3.1 Digitization of Streams: With the help of tool in extension Stream Digitizing Extension. Fig. 24

3.3.2 Digitization of Contours: With the help of tool in Extensions Stream Digitizing Extension.

Fig. 25

3.3.3 Insert LANDSAT ETM+ Image:Add LANDSAT image and georeferenced it in the same way as we did in toposheets. Fig. 26

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3.3.4 Digitized the LANDSAT ETM+ image with Lineaments:The lineaments show the zones of dominant deposits of Iron ore in hilly terrain.

Fig. 27

3.3.5 Merge image of all themes on LANDSAT ETM+ image on zooming:-

Fig. 28

3.3.6 Contours present as elevated points of same elevation: All points of same contours show the same elevation. Fig. 29

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3.4 Terms in Methodologies:3.4.1 LANDSAT (ETM+) Image P/R- 142/47:The ETM+ images are of LANDSAT 7 that contains a total of 8 bands; 6 in the visible and Near-Infrared (VNIR), 1 in the Thermal Infrared (TIR), region of the electromagnetic spectrum, and 1 panchromatic channel (band 8). Spatial resolution is 15 m for the panchromatic band, 30 m for VNIR bands, and 60 m for the TIR bands. Table 4: LANDSAT TM bands and their application Bands

Wavelength

Application

TM1

0.45-0.52 (blue)

TM2

0.52-0.60 (green)

TM3

0.63-0.69 (red)

TM4

0.76-0.90 (near IR)

TM5 TM6

1.55-1.75 (mid IR) 10.4-12.5 (thermal IR)

TM7

2.08-2.35 (mid IR)

Coastal water mapping/vegetation discrimination. Forest classification, manmade feature identification Vegetation discrimination and health monitoring, man-made feature identification Plant species identification, man-made feature identification Soil moisture monitoring, vegetation monitoring, water body discrimination Vegetation moisture content monitoring Surface temperature, vegetation stress monitoring, soil moisture monitoring, cloud differentiation, volcanic monitoring Mineral and rock discrimination, vegetation moisture content

Fig. 30 Reflectance spectra of the iron oxide (hematite) and iron hydroxide (goethite) (from Clark et al., 1993).

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3.4.2 Georeferencing:Georeferencing is the process of scaling, rotating and translating the image to match a particular size and position. It’s necessary because a raster image is made up of pixels and has no particular size. Without georeferencing, the vectorised GIS drawing size is determined by the raster's pixel dimensions (the width and height of the raster in pixels). This image sizing will usually bear no relationship with the dimensions of the drawing that the raster represents. 3.4.3 ArcView Shapefiles:ArcView uses files called "shapefiles" to store its data. A "shapefile" actually consists of three different files: shape description file (.shp); an index file linking shape to attributes (.shx); and, an attributes database table (.dbf).

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Chapter4. Results and Interpretation:4.1 General:The results, which have been derived from digital image processing of remotely sensed datasets of the study area, are presented in this chapter with the aim of extracting lithological, structural and lineaments information that might be utilized in locating mineral deposits of Iron occurrences in the area of investigation. Several types of image processing have been employed in this procedure, which are each described below in their respective subsections. The rocks in the area have undergone different orogenic episodes and as a result respond differently to the tectonic deformation that has affected the terrain hence the numbers and the sizes of the lineaments (fractures extracted from different lithologies (schists, gneisses, quartzites etc.) detected on the satellite imagery.

4.1.1 Vegetation:The result obtained from the satellite image interpretation has demonstrated the usefulness of remote sensing in lineament mapping and analysis in delineating productive zones of Iron ore mineralization. In this process, before any lithological discrimination was performed, the contribution to the area scene by vegetation cover identified first using LANDSAT TH band in RGB colors, which revealed vegetation as red features mostly along streams and alcoves and channels. The area with dense vegetation shows the high amount of shales and phyllites and the barren area shows the gneiss, quartzite and granitic rocks. 4.1.2 Streams:As we demonstrate here that most streams are follows the fault lines by the straight motions. Linear valleys eroded by rivers or streams with limited meander development are due to the exploitation of fractures by weathering and then by erosion. They occur at scale from the very local to regional. Short linear sectors (up to a few kilometers but commonly just a few tens meters) may be related either to joints or faults. Longer straight rivers are almost certainly due to the influence of fault. At the local scale some short stream lines are essentially straight though irregular in detail but within the channel obvious fractures are either few or discontinuous, or absent. These clefts or slots are probably due to linear zones of strain which, given further, continued or renewed stress may eventually develop into fractures. Angular stream patterns consist of essentially

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straight streams which join in angular junctions. The disposition of the various elements reflects the spacing and arrangement of fractures in the host rock. In some of the granite outcrops streams are disposed roughly normal to one another the fractures are disposed at acute angles to one another and have given rise to a compressed zig-zag pattern. 4.1.3 Lineaments:Lineaments are straight or gently arcuate structural lines (faults, cleavage, fold axes) which, being zones of weakness, find expression in the landscape. Some straight river sectors are aligned in parallel with regional lineament patterns. They are due to recurrent or resurgent shearing and can be identified at all scales from the local to the regional. Lineaments have been exploited not only by ascending mineral-bearing liquids from the mantle but also by exogenic weathering and erosion leading to linear streams and valleys. Whereas epigene rivers exploit lineaments and become entrenched from above, structural control can also be imposed from below. They may include straight stream valleys, contrasting tone, straight ridges and alignment of vegetation (Roy et. al. 1993, Ross and Frohlich, 1993, Cepda, 1994, Hatcher, 1995 and Sabins, 1997). Lineaments may be made up of geomorphic (relief) or tonal (contrast differences). They may include straight stream valleys, contrasting tone, straight ridges and alignment of vegetation (Roy et. al. 1993, Ross and Frohlich, 1993, Hatcher, 1995 and Sabins, 1997), Cepda, 1994, Hatcher, 1995 and Sabins, 1997).

Zones of Iron Ore Deposits.

Fig. 31 29

4.1.4 Contours:The most useful feature on the map is the contour line. A contour line is a line on the map joining points of equal height. The Vertical Interval is the height between each contour – this will be shown on the map. So what is a contour feature? It’s pretty simple really there is finite number of types of contour feature:     

ring contours - which portray knolls and hills (RC) gentle slopes (GS) medium slopes (MS) steep slopes (SS) ridges - which can be small, medium or large (R) flat areas - the absence of contours can be useful (F)

The illustration map shows examples of all these features-

R

GS

F MS

RC SS

Fig. 32

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4.2 Validation of the Results:The validity of the applied remote sensing techniques can be determined by comparison between the applied methods and effectiveness of their results with spectral and nonspectral ground data (ground truth) in exploration area. In the present study, there were no ground spectral data and the validation was performed on geological map as well as the mineral inventory conducted by GSI and NMDC. The results indicated matching of possible iron deposition along the faulted zone presented by dense lineaments in the map and the same locations of fault zones coincide with the geophysical anomalies according to the survey conduct by GSI which obtained during reconnaissance surveys. On the basis of prominent lineaments extracted from the area, it is believed that fracturing postdated the folding episodes in the area. The overall picture of the study area from image interpretation and field studies revealed that the study area has been seriously affected by tectonism on a large scale and the series of folds and faults detected on the image are products of geotectonic activities. Also, the area seemed to have undergone several stages of tectonic deformation as detected on the imagery which can be confirmed by intensive geologic and structural mapping of the area which the next focus of this study in border to understand better the geologic setting and the tectonic evolution of the area.

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5. Conclusion:Multispectral remote sensing (Landsat +ETM) image and interpretation proved to be useful in identification, detection and delineation of lithological rock units and geological structures associated with iron ore deposits in the area of Bailadila. Geologic mapping is important in evaluating mineral resources of a country place like Dantewada and Bailadila, in which exploration of its prospecting regions has always been a challenge due to inaccessibility of technology, financial resources and naxalism. To facilitate and reduce exploration expenses, it is best utilizing remote sensing capabilities for such tasks in order to obtain better coverage and accuracy with significantly reduced time and cost. The N-S orientation set represents extensional fractures which form parallel to the direction of maximum principle compressive stress (σ1). Moreover, lineaments and major structural features can better be observed and studied by using satellite images and or aerial photos. This might be attributed to the fact that the large size of those features makes them difficult to be noticed in the field. There are two major systems of fractures. The first system of fractures is along NNESSW direction and the second one is along NNW-SSE direction. We do not wish to push the analysis presented here too far. We have (deliberately) oversimplified many aspects of the problem of elucidate the type of lithos present in the remote areas by satellite imagery interpretations. The question is how much area still have capability of have Iron ore in there is solved by the previous excavated areas, all present mined area is located at faulted lineaments along the deformed zones, so it’s be a easy perception that other lineaments too have capable zones of Iron ores. So, in the present report , the phenomenon and formation reasons of formation of Iron ore deposits alignment along the fracture zones or lineaments, which recognized by tonal difference, shades interpretation, contours maps and stream straightness etc. told that certain tectonism played a role in the deposition in perfect time and conditions required for the origin.

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6. References  Cosmas Pitia Kujjo, Application of Remote Sensing for Gold Exploration in The Nuba Mountains, Sudan.  Ross, A. L. and Frohlich, R. K., 1993. Fracture traces analysis with a Geographic Information System "GIS": Association of Engineering Geologist, v. 30, n. 1, p. 87-98.  Roy, D. W., Schmitt, L., Woussen, G., and Duberges, R., 1993. Lineaments from Airborne SAR images and 1988 Saguenay earthquake, Quebec, Canada: Photogrammetric Engineering, v. 59. p. 1299 -1305.  Cepda, J. C., 1994. Fracture orientation and distribution on the Kaibab Plateau of northern Arizona: Rocky Mountain Association of Geologist, v. 31, n. 3, p. 77- 83.  Hatcher, R. D., Jr., 1995 Structural Geology, principles, concepts, and problems, 2ed edition: Prentice Hall, New Jersey, 525 p.  Mustafa M. Hariri and Osman Abdullatif, USE OF THE GIS TO DELINEATE LINEAMENTS FROM LANDSAT IMAGES, DAMMAM DOME, EASTERN SAUDI ARABIA.  Shankar Babu Pokharel, Remote Sensing and GIS Analysis of Spatial Distribution of Fracture Patterns in the Makran Accretionary Prism, Southeast Iran.  C.R. Twidale, River patterns and their meaning, Earth-Science Reviews 67 (2004) 159–218, Geology and Geophysics, School of Earth and Environmental Sciences, The University of Adelaide, G.P.O. Box 498, Adelaide, South Australia 5005, Australia  O.S. Ayodele1 and I.B. Odeyemi, Analysis of the lineaments extracted from LANDSAT TM image of the area around Okemesi, South-Western Nigeria

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