3.1 Introduction
CHAPTER-III
GEOLOGY OF THE AREA
(A) Role of geological studies in the Environmental and Resource evaluation:
Geological factors greatly influence man and his activities. The discipline of environmental
geology embraces the whole gamut of human use of the earth. A clear comprehension of
the dynamics and mechanisms of the various earth processes that give rise to mineral
deposits, control movement and storage of surface and ground waters, shape terrain
morphology and landscapes and lead to soil type formation is an essential prerequisite in
understanding, preserving and restoring natural environment. A geologist is well equipped
to evaluate the capability of the earth for providing water, minerals and other resources, to
select appropriate sites for construction of engineering structures and for disposal of water
and pollutants and to identifY lands for supporting agriculture, forestry, industries and
urban centres.
The major areas in which the role of earth sciences are of vital importance include terrain
evaluation, landuse planning, hydrogeology, water management, earth resources
conservation and management, geological hazards, engineering structures, waste disposal,
pollution control and alternate sources of energy (V aldiya, 1987).
(B) GeologicaV lithological maps incorporate a large and varied geological data from field
observations and field and laboratory measurements, but they are in part subjective because
field measurements are always limited by rock exposure, accessibility, man power
resources and the spectral range under which a human being can see.
But with remotely sensed satellite data, having manifestation of the wide spectral and
emittance characteristics of the surface material, synoptic view and repetivity. it is possible
to obtain certain structural and lithologic information more efficiently than those which can
be achieved on the ground. A major hurdle in geological remote sensing is that invariably
the surface outcrop is covered by the vegetation or weathering products, so that the various
Geology of the Area
---------------------------------------------------------------
strands of evidence have to be taken to infer the lithology or structure from remotely
sensed data (Barret and Curtis, 1982).
For better delineation of lithological and structural features, remotely sensed data must be
used along with the existing field geological map (Goetz and Rowan. 1981) and the result
of geophysical and geochemical surveys through digital image processing and geographical
information system (Abrams et.al., 1983; Lyberis et.al., 1990).
One of the basic information that remotely sensed data can provide for the exploration of
the groundwater, mineral and hydrocarbon, and location of power plants and dam sites and
earthquake studies is lineament pattern of the area (Rowan. 1975). These are the alignment
of regional morphological features and zonal features that in many areas are the surface
expression of fracture or fault zones, ranging from few kilometre to hundred of kilometres
(Goetz and Rowan. 1981; Drury, 1986; Sabins, 1987).
In a hard rock terrain, lineaments interpreted from satellite imagery represent faults, joints
and dykes of several ages. Such fissured rocks are more and more susceptible to deep
weathering and are therefore ideal locations for bore well drilling (Greenbaum, 1992).
In mineral exploration, space borne data has been used in three ways (Amos and
Greenbaum, 1989; Rowan et.al., 1977; Rowan and Wetlaufer, 1981; Sabin, 1987):
1. Delineation of regional lineament, along which groups of mining zones may occur
l. Delineation oflocal fracture pattern that may control individual ore deposits
3. Identifying features directly related to mineralization, such as alteration zones,
alteration haloes, gossan and specific host rock association.
The hydrothermally altered country rocks contain distinctive assemblage of secondary or
alteration minerals that replace the original constituents. In regions where bedrock is
exposed, multispectral remote sensing have been found useful for recognising altered rock
because their reflectance spectra differ from those of country rocks (Rowan et.al., 1977).
Geology of the Area
With digital image processing, it is possible to manipulate and combine a large number of
spectral bands and images or other types of data sets. Digital image processing techniques
applied to geologic problems include contrast enhancement and spatial filtering to enhance
morphological or structural information, arithmetic operations such as ratio of spectral
bands to enhance spectral reflectance d.iffereoces and suppress systematic effects such as
topography. Statistical analysis is used to reduce dimensionality in data set containing many
spectral bands or other variables (Abram et.al., 1983; Amos and Gt-eenbaum, 1989).
3.2 OBJECTIVES:
The geology of the area was studied with the following main objectives:
1. To delineate various litho-units and to locate the mineral resource of the area
n. To delineate lineaments through visual interpretation of satellite image and digitally
processed images.
m. To find out the lineament frequency density and lineament intersection density of the
area
N. To recognise litho-units and structures which are potential from groundwater point of
view
v. To estasblish the interrelationship between soil erosion and various litho-units
VI. To estasblish interrelationship between soil physiography, land capability, landuse and
various litho-units
3.3 METHODOLOGY
I. Existing geological maps and literature were collected.
D. Visual interpretation of hard copy of IRS-ffi LISS- ll satellite image was done in
conjunction with SOl toposheet. As area is covered with vegetation or weathered
mantle, digital image processing was done to enhance structures and litho-boundary.
Ill. Tentative geological map was prepared using visuallY interpreted maps, digitally
enhanced products and existing geological maps. Table 3.1 show the image
characteristics of various lithounits. The digital image processing techniques and their
significant results have been given in Table 3.2.
26
Table-3.1 Image Characteristics for Different Litho-units
Utho-unlts Tone/ Colour on FCC 432 Drainage Pattern Texture Structure Land use Morphogentlc Trend line chancterlstlcs
1) Dhandraul Reddish brown (Vegetation covered) to Coarse, Sub-paraUel Coarse Flat top surface Forest dense, Fanning plateau litho-contact Quartzite reddish yellow (agricultural land) agriculture sharp, trend line
visible l) Scarp sandstone ButT creamy Parallel, medium Medium Steep slope Degraded barren Scarp face 3) Bijaigarh shale Creamy Parallel to sub-parallel medium Forest, agriculture Valley portion Trend line not
sharp 4) Upper Quartzite Greenish brown to reddish yellow Coarse, sub-parallel Medium to Trendline Mainly forest
coarse visible 5) Silicified shale Greenish brown to reddish yellow, Coarse, sub-parallel Fine _,,_ Forest
reddish 6) Lower Quartzite Brownish red to cream Medium, sub-parallel Fine to medium 7) Rohtas, Reddish brown to greenish brown at Medium, sub-parallel Fine to medium _,,_ Forest, agriculture
limestone, Shale forested part, reddish to yellowish red at agricultural land
8) Glauconitic beds Reddish brown to greenish brown at Medium, sub-parallel Fine to medium _,,_ Mostly agriculture, forested part reddish to yellowish red at forest agricultural land
9) Fawn 1st Reddish brown to greenish brown at Medium, sub-parallel Fine to medium _,,_ Mostly agriculture, forested part, reddish to yellowish red forest at agricultural land
10) Olive shale Reddish to chocolate brown Medium sub-parallel Fine to medium "
agriculture, forest 11) Porcellanite Brownish grey (drg. forest), red Medium, parallel Medium to Dissected Agriculture, Denudational hill
(agriculture) coarse surface degraded forest 12) Kajarhat Greyish brown to yellowish grey, white Parallel to sub-parallel Medium to Dissected Mining, Linear structural
limestone at mining cream to red at agricultural coarse agriculture, barren sheet with land trendline
13) Arangi shale Brownish grey Coarse, parallel Fine Linear Agriculture, dry Side slope of linear forest structural hill
14) Patherwa Coarse, parallel Fine Linear Degraded forest Side slope of linear formation structural hiU
15) Lotan form Reddish brown to brown and creamy at Trellis Medium to Ridge, valley Forest Ridge and valley degraded forest coarse topography of the
dissected hill
Geology of the A. rea
IV. Field work was carried out at selected sites to check and modify the geological and
lineament maps and to collect other structural information.
V. After field check final geological (Plate 3.la) and lineament map (Plate 3.1b) were
prepared.
VI. The direction, length and number of lineaments were measured and rose diagrams of
frequency and length were prepared to depict major stress direction.
Vll. Lineament map was divided into one square km grids and the number of lineaments
and number of lineament intersections within each grid were counted at the central
point of each grid separately. These were contoured using triangulation method, and
the lineament density and lineament intersection density maps were prepared.
Table- 3.2
DIGITALLY ENHANCED IMAGES AND FEATURES HIGHLIGHTED
Combination Feature highlighted
FCC432 Highlight broad litho-units
Band 4 (Laplacian Highlight litho-boundary, landform and
filter) lineament
PC2 Highlights all lineaments, litho contacts very
prominently, folding and faulting
Hybrid FCC, PCI, Highlights structure and litho contact In
PC2, PC3 Upper Vindhyan and Mahakoshal,
lineaments
Hybrid: 'FCC, 4 Differentiate Porcellanite and limestone
(LF), 3 F), 2 (Kajarahat) and litho contact
3.4 GEOLOGY OF THE AREA
3.4.1 Regional geological set up: The area is comprised of two distinct groups of
geological formations:
I. The Pre-Vindhyan meta-sediments and volcano-sedimentary sequence of early
Proterozoic (Plumb and James, 1986), known as Mahakoshal group of rocks (Rogers,
28
Plate 3.la : Geological Map
LINEAMENT MAP OF DAtA · RENUKUT AREA
80NBHADRA OIST. UP, INDIA
Plate 3.1b : Lineament Map
Geology of the Area
I. 1986; Dutta, 1986) consisting of phyllite, quartzites, schists and marble, banded iron
formation etc. (Roy and Bandopadhyay, 1990) occupying a large part of the area.
IT. The Semri and Kaimur group of the Vmdhyan super group (Auden, 1933),
conspicuously exposed in the northern part of the area.
The Semri group of rocks (Lower Vmdhyans) consisting of limestones, shales, glauconite
beds. porcellanite, silicified rocks and basal conglomerates, sandstone and shale (now the
Patherwa formation and Arangi shale; Prakash, 1967) are exposed along the Son river on
either side, while the Kaimur group of rocks (Upper Vmdhyans) consisting mainly of
qUartzite, sandstone and shale form conspicuous by high relief in the extreme north of the
area (Auden, 1933).The sequence litho-stratigraphy of the study area is given in the Table
3.3.
3.S DISTRIBUTION AND CHARACTERISTICS OF DIFFERENT LITHO-UNITS:
3.5.1 Mahakoshal group
3.5.1.1 Panoi formation: The rocks ofParsoi formation are exposed north ofBelguri nala
and south of Dala and Obra. These are comprised of chlorite-phyllite and schist with
interbands of meta-semipelite, meta-sub-greywacke and meta-volcanics. Locally bands of
marble and quartzite are seen in the formation towards the base.
The rocks form uneven topography, locally with prominent strike ridge having hogback
features formed due to differential weathering of quartzite and schist bands. The schist
bands occupy valley portions in between the quartzite ridges. Drainage are coarse and
forms joint controlled trellis pattern. On satellite image (FCC 432), these are reddish brown
to brown when forested and creamy and reddish when covered by degraded forest and
agricultural land respectively. These are distinguishable from Vindhyan group of rocks by
its strike ridge trend and with Lotan formation by its more dissected and erosion prone
nature.
10
Table-3.3
LITHOSTRATIGRAPIDC SEQUENCE IN PART OF SON VALLEY AREA
(after Auden, 1933; Prakash, 1967; Iqbaluddin & Moghni. 1980; Dutta, 1986)
Groups Formation
Upper Upper Kaimur Group Dbandtaul Quartzite
Scarp Sandstone
Lower Kaimur Group Bijaigarb Shales
Vmdbyan Upper Quartzite
Supergroup Silicified Shales
Lower Quartzite
Lower Semri Group Rohtas Umestone & Shale Formation
Khenjua formation
Glauconitic beds
Fawn Limestone
Olive Shales
Porcellanite Formations
Kajarahat Limestone
Arangi Shales
Patherwa formation
Lotan formation*
Mabakosbal Parsoi formation 0
........ • Phyllite. meta-subgraywacke, meta-protoquartzite. marble and quartztte
e Sdsist. phyllite. quartzite. metasubgn:ywacke. mcta-protoquartzite
Geology of 1M Area
The phyllite and schists of Parsoi formation •e green, greenish grey and olive green in
colour. The rocks are fine to medium grained comprising quartz, chlorite and sericite. The
sheet minerals show lepidob1astic structure defined by preferred orientation of their
pinnacoidal faces parallel to the regional foliation. Locally, the phyllites are very fine
grained and porphyroblastic minerals are not well developed to make their identification
possible by unaided eyes.
Outcrops of marble were seen at Obra and Nmgha. These ocaJr as interstratified bands
with a high degree of lenticularity. In Obra, near the western abutment of the railway
bridge, marble is seen south ofKajarahat limestone outcrop. It is white, coarsely, crystalline
dolomitic marble.
The marble band in the Ningha shows cement grey colour on the weathered surface but on
the fresh surface as seen in the quany &ce, it is milky white. It is coarsely crystalline
comprising of predominantly calcite and is free from impurities.
These are tightly folded with E-W trend and dipping steeply(~ 70°) due north or south,
forming linear synclinal ridge and aotidinal valley topography. These are well jointed. The
strike trend and joint pattern give rise to characteristics trellis drainage pattern.
3.5.1.2 Lotan formation: These are exposed south ofBelguri nata in the study area. These
rocks are relatively coarser and schistose than the underlying phyllitic sequence of Parsoi
formation. Frequency of ocaJ.I'J"eDCe of meta-sub-greywackelmeta-protoquartzite/lithic
arenite is more in this formation, south of Jogidih village than in the Parsoi formation.
These rocks also form ridge and valley topography, but having higher relief than in the
Lotan formation. Softer rocks like scbists occupy mostly the valleys and side slopes while
the resistant quartzites form ridges.
On satellite image, they show cheny brown to brown tone on forest covered area, but
creamy to reddish on agricultural laud. These are less dissected than the Lotan formation.
Though there is no distinct image dlaracteristic to demarcate its boundary with Lotan
32
Geology of the Area
formation, but the prominent E-W running lineament along the Belguri nala, fonns the litho
contact between the two.
These are interstratified sequence of schist, meta-protoquartzite and meta-sub-greywacke.
The schist is dark green, medium to fine grained comprising predominantly of chlorite and
quartz with biotite and sericite OCCUlTing as common constituents. The schist around
Renukoot near the contact with migmatite shows higher grade of metamorphism manifested
by development of quartz muscovite schist. The sheet minerals show lepidoblastic structure
defining the first schistosity in these rocks.
Meta-sub-greywacke and meta-protoquartzite bands are seen interbedded with schist and
phyllite. These bands megascopically, at outcrop level can be distinguished from phyllite
and schist by their coarser texture and quartzose composition. The rocks are dusky to
subdued green in colour, medium to coarse grained comprising quartz, sericite, chlorite
and a little biotite.
The quartzite is greyish in colour, medium to coarse grained and at places sericitic. The
development of foliation is conspicuous, manifested by slight elongation of quartz grains
and preferred arrangement of sericite.
These are also tightly folded with E-W trend and dipping steeply (~ 70° ) due north or
south, forming linear synclinal ridge and anticlinal valley topography.
3.5.2 VINDHY AN SUPERGROUP
3.5.2.1 Pathenva formation: This is named after the nata of this name that occurs to the
south-west ofHardi village where a representative section is well exposed (Prakash, 1967).
The basal contact of this formation is unconformable with the basement rocks (Mahakoshal
Group) and towards the top this formation passes sharply into shales.
These are exposed as a narrow linear structural hill south of Data cement factory aligned in
East-West direction upto Hardi. The absence of any wide outcrop of this formation in the
33
Geologyofthe Area
area is due to faulting (Prakash. 1967). On satellite image it can be easily identified due to
its brownish grey tone with fine texture and conspicuous linear alignment.
These arenaceous rocks are usually formed of a sequence of unsorted pebble beds, which
are overlain by grits and graded pebble beds with multiple, often tangential, cross
laminations. The parallel or cross-laminations are usually made up of sbaly laminae which
are often limonitic or hematitic. Overlying there are lenticular dirty sandstones, which pass
upwards into arenaceous shale. Carbonate forms a common constituent of this fonnation
and occurs as a isolated, coarse, angular fragments in the sandstone.
3.5.2.2 Arangi formation: These are formed as side slope of the main ridge of the
Patherwa formation. This consists of an alternating sequence of dark grey and
carbonaceous shales with lentia.dar carbonate and minor pseudo-conglomerate beds. The
formation at its top contains silicified beds and a hematitic regolith in the Kajarahat and the
Patherwa nala sections. The presence of the regolith is significant as it indicates exposure
and leaching of the underlying beds after deposition.
3.5.2.3 Kajarahat limestone: This unit overlies unconformably over Arangi Shale
formation (Prakash, 1967). These are exposed as linear structural hills, residual hills and
inselbergs protruding in the weathered pediment plain in and around Obra, Kajarahat, Billi,
Dala, Kota, Dyotara village.
On satellite image, it can be seen with greyish brown, yellowish grey to white tone at
mining site. The formation comprises predominantly of limestone with dolomitic limestone/
dolomite towards top of the sequence. The outcrop pattern is reflected by strike of bedding
occurring as ruwares, inselberg and tors.
Kajarahat limestone in the Billi-Obra section is microcrystalline, light grey, bluish grey to
buff in colour generally forming well bedded smooth outcrops. These limestone have a
southerly dip of 12° or more even occasionally vertical. In the Kajarahat, Billi section it is
folded into anticlines and synclines.
34
Geology of the Area
At places in the triangular outcrop near Billi where interconnecting joints are predominantly
developed, intense solution action and local internal drainage can be seen.
3.5.2.4 Porcellanite Formation: It is well exposed all along the southern part of the river
Son in and around Bari, Gauradah as residual hills. These residual hills on satellite image
show brownish grey tone.
The Porcellanite formation contains volcanic products which were presumably
contemporaneous to the Malani volcanics of the western Rajasthan (Kumar, 1985). These
are fine grained, greyish white rocks, characterised by two sets of major joints. After
breaking, it gives out conchoidal fracture with extremely fine shaped slinters.
Railway line cutting between Chopan and Billi exposes an excellent section of Porcellanite.
Moving from Billi towards Chopan, one can observe a complete section of Porcellanite
formation. The contact between Kajarahat limestone and Porcellanite is gradational, the
limestone imperceptibly passing into Porcellanite with the gradual increase in chert.
Occurring as interbands within Porcellanite, near Bari, is dolomite, showing elephant- skin
weathering. Towards the top of the sequence in the railway section banded Porcellanite is
seen. It comprises of silcified laminae showing well developed bedding defined by
alternating light and dark coloured layers.
Locally bands of green Porcellanite are seen in the Chopan-Obra road section, north of
Billi. The green Porcellanite is more cherty than banded Porcellanite and is free from
allogenic constituents.
3.5.2.5 Kheojua formation: It consists of three subdivisions viz. Olive shales, fawn
limestone and glauconitic beds. These are indistinguishable on satellite image.
Oliw! slr.ales: These pale olive green shale are exposed in the railway section north of level
crossing of Dala-Chopan road and in and around Chakaria village. In the railway section
the conformable contact between porcellanite and shales is present. The banded porcellanite
35
Geology of the Area
is succeeded by an alternating sequence of olive shales and subdued green semi-pelites. The
rocks are distinguishable from underlying porcellanite by their distinct colour, absence of
silicification and preponderance of allogenic material. The bedding in the shales is well
developed and is marked by bedding plane irregularities.
Fawn limestone: It is exposed along the Son river bank between Kandhaura and Chikra
villages. It is fawn in colour, siliceous and well bedded. Typical elephant skin weathering is
developed at the river bank near Chikra village.
Glt~~~collitic beds: It occurs as narrow belt and exposed around Sasnai village. The pale
green sandstone i~ silty in nature and characterised by the presence of glauconite. In
weathered surface, glauconite is oxidised to rusty brown iron-oxide (limonite) and the beds
show pale colour.
3.5.2.6 Rohtas limestone & shale formation: It forms the uppermost horizon of the
Semri group (Lower Vindhyan) and consists mainly of grey coloured, siliceous limestone
interbedded with thin shale. A road laid down by U.P. Forest Department runs in the
eastern and western part of it.
3.5.2. 7 Kaimur group: It forms the lower most horizon of the upper Vindhyan. The
K.aimur group is mainly arenaceous in nature and is subdivided into Lower Kaimur and
Upper Kaimur. The former includes lower quartzite, silicified shales and upper quartzite.
and the latter one consists of scarp sandstone and Dhandraul quartzite.
Lower Kai~t~~~r quartzites and Bijaigarh shales: The sandstone is silicified in nature and
light grey in colour. It is well jointed. The Bijaigarh shale is exposed all along bottom of the
scarp sandstone forming gentle scarp face. It is dark in colour and support sparse
vegetation.
Upper Kai~t~~~r SCtli'Jl sandstone and Dhandraul qutlrlzite: The scarp sandstone form
steep scarp face. The scarp sandstone is well jointed and support very little vegetation. The
Dbandraul quartzite lies over the scarp sandstone. It also forms wide plateau top with
36
Geology of the .Area
minor scarp. The plateau at a few places, after erosion gives rise to mesa form. It is fine
grained and thickly bedded.
3.6 STRUCTURE
The area studied depict various diastrophic structures such as antiform, synform, minor
folds, lineaments, faults, shear zone, fracture, joints and other structural elements.
Dominant structural features brought out from interpretation of satellite image of IRS-ffi
LISS-ll and by digital image processing. The synoptic view provided by the satellite images
has helped in bringing out the regional geological and tectonic frame work of the area as
well as its lineament fabric.
During the field work, other structural details like bedding, foliation, dip and strike, joints,
minor fold and faults, shears etc. were studied.
3.6.1 Lineaments
3.6.1.1 A lineament is a mappable linear or curvilinear feature of a surface whose parts
align in a straight or slightly curving relationship that may be the expression of a fault or
other line of weakness. The surface features that make a lineament may be geomorphic or
tonal. Straight stream valleys and aligned segments of valleys are typical geomorphic
expressions of lineaments. A tonal lineament may be a straight boundary between
contrasting tone or a stripe against a background of contrasting tone. Differences in
vegetation, moisture content and soil or rock compositions account for most tonal
contrasts (Sabins, 1987).
3.6.1.2 Lineament Analysis: Lineament traces have been visually interpreted and
delineated from the satellite data (IRS LISS II FCC and digitally enhanced images). The
lineament map is shown in Plate 3. lb. Lineament density map and lineament intersection
density map have been prepared using the lineament map by counting the number of
lineaments and lineament intersections respectively within 1 km square grids and
contouring the values (Plate 3.2a and 3.2b).
37
Plate 3.2a : Lineament Density Map
Plate 3.2b : Lineament Intersection Density Map
Geology of the Area
For the purpose of lineament analysis, the lineaments were grouped into azimuth classes
corresponding to 10° intervals and the number and total length of lineaments within each
azimuth classes were measured (Table 3.4). Using these data frequency - azimuth and
length-azimuth diagrams were prepared as rose diagrams (Figures 3 .1 and 3 .2).
4.6.1.3 Results of lineament analysis: The lineament map (Plate 3.1b) shows high
correlation of lineaments and their intersections in the central part of the study area within
the Parsoi formations of the Mahakoshal group of rocks that consists of phyllite-schist with
alternating greywacke quartzite which form ridge-valley landforms. This is also evident
from the lineament density map (Plate 3.2a) and lineament-intersection density map (Plate
3.2b). High concentration pockets of both lineament density and lineament intersection
tlensity are also observed in the Vindhyan terrain in the north-western part coinciding with
the Kajrahat limestone. Though the lineament density girdles do not show any distinct
trend, the lineament intersection density map shows the anomaly girdles trending NW -SE
and NE-SW directions.
In the lineament map the following four prominent lineaments have been traced, apart from
a net work of minor lineaments.
i) The E-W lineament in the southern part coinciding with the boundary between the Lotan
and Parsoi formations which is geomorphologically represented by a strike valley
separating the two.
ii) The E-W lineament in the northern part marking the boundary between Mahakoshal
group and the Vmdhyan supergroup of rocks, which has been interpreted as a fault and
represented by a linear structural hill.
iii) The NW -SE lineament in the central part which intersect the above lineament.
iv) The E-W lineament along the Son river in the NE part. Its traces are seen further west
in the form of discontinuous lineament.
39
Geology of the Area
Table 3.4
STATISTICS OF LINEAMENT ANALYSIS
Azimuth Range Frequency Length Frequency
(km) (%ge)
0-10 22 81.5 9.13
10-20 14 46.75 5.81
20-30 13 45 5.39
30-40 27 95 11.20
40-50 23 90 9.54
50-60 23 80.5 9.54
60-70 10 33 4.15
70-80 5 24 2.08
80-90 4 22 1.66
90- 100 1 15 0.42
100- 110 5 22.75 2.08
110- 120 9 23.5 3.73
120- 130 14 63.5 5.81
130- 140 20 84 8.30
140- 150 17 62.5 7.05
150- 160 13 40.25 5.39
160- 170 13 57.75 5.39
170- 180 8 31.75 3.32
40
l I I I I
Fig. 3-1 LINEAMENT FREQUENCY AZIMUTH ROSE DIAGRAM
1 0 1 2 J '- SliM
Fig. J.2 LINEAMENT LENGTH AZIMUTH ROSE DIAGRAM
Geology of the Area
The azimuth-length and azimuth-frequency rose diagrams (Figures 3.1 and 3.2) show three
major directions of lineaments tn the area. They are,
i) NE-SW (varying between N30-60E)
ii) NW-SE (varying between N30-60W)
iii) N-S.
The formations in the area exhibit conspicuous E-W trending tight folds with steep axial
planes, indicating that the greatest principal axis of stress that has caused deformation was
along N-S direction, and the least stress axis along E-W. The NE-SW and NW-SE oriented
lineaments thus represent conjugate set of shear fractures resulting from .this stress. The N
S set of lineaments represent the extension fractures along this direction.
4.6.2. Other tectonic structures: This has been dealt separately for major lithounits of
Mahakoshal group and Vindhyan supergroup.
4.6.2.1 Tectonic structures in Mahakoshal group of rocks:
i) Foliation: There are two directions of cleavage planes found as S2 and S3 cleavage
planes.
S1 cleavage: This is the axial-plane schistosity of Fl folds in the area, manifested by
preferred orientation of sheet minerals (Sericite, chlorite and biotite) with their flat faces
parallel to schistosity.
SJ cleavage: It is the axial plane cleavage of F2 folds and is developed as slaty cleavage.
Locally in the outcrop ofLotan formation, this cleavage is pervasive and has obliterated the
earlier s2 cleavage.
ii) Shears: Minor displacement along different sets of joints and fracture planes have been
observed locally resulting in thin zones of brecciation and development of slickenside. ln
the section examined near Gurmura railway station, two sets of shear trending WNW-ESE
are well exposed, one set displaying dip sub-vertically to south and the other at 20° to 30°
towards south.
42
Geology of the Area
iii) Joints: The joints in Mahakoshal group of rocks are mostly tight. Following sets of
joints have been observed in the field.
Orientation of Joint Sets
Strike
1.) N-S, dipping 80°W to 80° E
2.) E-W, two sets dipping 45° Nand 70° S
3.) NNE-SSW: vertical
4.) NNW-SSE: vertical
5.) NW-SE: vertical
6.) ESE-WNW: vertical
iv) Folds: These formations are tightly folded with E-W trends and dipping steeply to north
or south and forming linear ridge and valley topography, with synclinal hills and anticlinal
valleys.
v) Faults: The Mahakoshal group have clear faulted contacts striking EW with the
Vindhyans in the north as well as with migmatite in the south. Along the fault zones, fault
breccia is observed. The fault plane runs along the stream course.
3.6.2.2 Tectonic structures in Vindbyans: The lower Vindhyans are subjected to more
deformation than the upper one. The structural deformation in the Semri group of rocks
were observed in the field.
i) Joints: The Porcellanite formation is highly jointed and two sets of joints are more
prominent.
• Striking N 70° W- S 70° E and dipping 700 to SSW
• Striking N 30° E - S 30° W dipping 75° to SE
The hexagonal block of Porcellanite of different sizes indicate columnar joints. The vertical
joints are very common in Dhandraul quartzite and scarp sandstone. The prominent joints
in Dhandraul quartzite are:
l)WNW-ESE 2)NE-SW 3)NNW-SSE 4)NW-SE
43
Geology of the Area
ii) Fohls: These are seen on mesoscopic and macroscopic scales in the porcellanite near
Billi and near the railway crossing of Dala-Chopan road. These are flexural type of fold,
where southern limb of syncline is having relatively higher inclination.
iii) Ftllllts: The contact ofVmdhyan and Mahak.oshal is faulted one. The continuous hill of
folded Porcellanite occupying south of the river Son is faulted along N75°W-S75° E,
showing displacement with its eastern block as upthrown side. The Semri and Basal
formation is faulted near the village Hardi, displacing the Kajarahat limestone.
3. 7 Mineral Resource of the Area
The rocks and minerals of economic significance in the area are as follows (Plate 3 .3a)
1) Cement grade limestone: Extensive deposits of cement grade limestone exists within
the Kajarahat limestone horizon of the Vindhyan. Locally, it is being worked for
manufacturing of cement at Data.
2) Chemical grade marble: The marble band of Mahak.oshal near Ningha is milky white,
apparently free from deleterious impurities. It is suitable for chemical industries. Presently it
is also fed along with Kajarahat limestone to Dala cement factory to upgrade the grade of
limestone required.
3) Flux grade dolomite/limestone: Its deposits exist in the Kajarahat limestone horizon
towards the top of the sequence near its contact with Porcellanite beds. The flux grade
dolomite of this horizon near Bari is being exploited by U.P.S.M.D. Corporation.
4) Road materials: Low grade dolomite and Porcellanite are being used as road metals in
the area.
5) Old gold working: Evidence of old gold workings associated with quartz veins located
about 2.5 km ofGunnura (Dwivedi et.al., 1995).
6) Radioactive minerals: Preliminary investigation by AMD has indicated the presence of
radioactivity in the matrix of basal conglomerate, near Jhingdandhi granite exposure, which
has probably acted as the source (personal communication). In the Parsoi formation also,
radioactivity has been reported within mineralised green colour rocks and highly pulverised
smoky quartz. (Khan et.al, 1989).
44
! UMESTONE (CEMEt•T GRAOE1 MAR81.E (CEMEriT CJ1'1AOE 1 UMI!SlOfll! II DOLOMITE tFLU l'IOAO MATER1ALS OU> QOLO WQR~UG RAOIOACTI\IE IIAIUI:RAI.fl
Plate 3.3a : Mineral Resource Map
Plate 3.3b : Dolomite Mines near Bari Village
Geology of the Area
3.8 SUMMARY OF THE RESULTS
• VISU81 interpretation of standard FCC image (FCC 432) and digitally enhanced
products together with geomorphological features, drainage pattern and
landusellandcover features were found tob useful in delineating and demarcating
various litho boundary in the area.
• The area is occupied with two distinct geological formations: (1) Schist, phyllite and
quartzite sequence of Mahakoshal Group of rocks exposed in the southern part of the
area; (2) the sedimentary seq~ of rocks of Vindhyans are conspicuous by their
presence on either side of the Son river. The Semri group of rocks of the Lower
Vmdhyans are well exposed on the south of the Son river and along the northern bank.
The Kaimur group of rocks of the Upper Vmdhyan stands out prominantly to the north
of the area fonning high hills with steep scarp faces. Dhandraul quartzite, the upper
most formation of Upper Kaimur in the area forms plateau and covers northern fiinge.
• The Mahakoshal Grooup have clear faulted contact with the Vmdhyans. Rocks of
Mahakoshal Group are tightly folded with E-W trend and dipping steeply(~ 70°) due
north or south fonning linear synclinal ridge and anticlinal valley.
• The Lower Vmdhyans have been subjected to more deformation than the upper one.
• Major lineaments of the area not only shows the tectonic structure, but also demarcates
the major litho units boundary between Semri Group with Mahakoshal Group and
Parsoi Formation with Lotan Formation.
• The azimuth-length and azimuth frequency rose digrams show three major directions of
lineaments in the area: (I) NE-SW (varying between N30°- 60°E); (ii) NW-SE (varying
between N30°- 60°W) and (iii) N-S.
• The major mineral resources of the area are: cement grade limestones, chemical grade
marble, flux grade dolomite/limestone, road metals, possible mineralization of gold,
other base metals and radioactive minerals.
46