Remote Sensing Techniques in Geoiogical and Geomorpliological Interpretation-An Exampie From The Bundi District. Rajasthan,

BY Hiyasat Musain

DtsssnTAfioNSummvBD m MunAi ruiFtLimNT FOR THE DEGREE OF MASTER OF mOLOSOBHY m GEOLOGY AT THEAUGAM MUSLIM tmtVEnSlTY. ALIGARH OCTOten, l$$7

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I 2 SEP 1988

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_:.EF:TIFICATE

This IS to csr-tii-' tnat Kr . Riyasat Husain has com­

pleted his research work under our jcint supervision in

partial -f u 1-f i 1 Imen t +or the at-jard o+ Haster o-f Philosophy

degr ee o-f the A i i garh Mu si irti Un i K>er si ty , A H garh , Th i s

work IS an original contribution to our knowledge o+ QSC'"I-

OQV and geornor phol ogy ot tne vindhyan basin in Buiidi •=>•: ^s.

1n Rajas than.

He . i s ailoi'jt-d to subrra t the work for tne a A-ard o-f

M.Phil degr ee o-f the A" i gar h 'u s 1 i m Un i y er s i t y , A1 i ga r h .

V KJA«XV,

< I QBAt.i^t>pIN> Pro-f. a no Director Remo t e Sen si ng App1i ca 11on Center -for Resources Evaluation and Geoenqineerin ALIGARH.

Pro-f . and Head Geosciences Di'..• i si on I n d i a n I n t-11 t ijte o+ Remote Sensing

DEHPADUN.

C O N T E N T S

List of Tables i

List of Figures ii

List of Plates iii

Prearnble Iv

Chapter-I INTRODUCTION 1

General Statement 1

Location and Extent of the 3 Area

Previous Work - A Brief Review 3

Data Source 6

Methodology 6

Acknowledgement 7

Chapter-II GEOMORPHOLOGY OF THE HREA 8 AND LANDSCAPE EVOLUTION

General Statement 8

Structural Hills of Bhilwaras 8

Pediment of Bhilwaras 10

Shallow Buried Pediment of 11 Bhilwaras

Buried Pediment of Bhilwaras 11

Structural Hills of Vindhyans 13

Structural Valleys of Vindhyans 15

Talus and Scree zone 16

Alluvial Plains 16

Drainage Pattern 17

Mej Sub-basin 17

Kural oub-basin 21

Planer Surtaces 22

Vinahyan Surface 22

Bhilwara -Surface 24

Chanibal Surface 2 6

Landscape Evolution 26

Chapter-Ill PHOTOGEOLOGY 29

General Statement 29

Bhilwara Supergroup 31

Hindoli Group 31

Pelitic Metasediments 32

Quartzites 33

Quartz Reefs 34

Vindhyan Supergroup 3 5

Kaimur Group 3 5

Kaimur Sandstone 39

Rewa Group 40

Panna Shale 41

Lower Rewa Sandstone 42

Jhiri Shale 43

Upper Rewa Sandstone 44

Bhander Group 46

Ganurgarh Shale 46

Bhander Limestone 48

Samaria Shale 49

Lower Bhander Sandstone 50

Sirbu Shale 51

Quaternary Deposits 52

Alluviujn 52

Chapter IV STRUCTURE 54

General Statement 54

Bhilwara Tect nic System 54

Foliation 56

Joints 56

Faults 57

Folds 57

Vindhyan Tectonic System 58

Faults 60

Great Boundary Fault 60

Satur-Talwas Strike Fault 62

Bundi-Indergarh Fault 53

Thikarda Right Lateral Wrench 63

Bundi-Satur Right Lateral 64 Wrench

Datunda Left Lateral Wrench 65

Ruppura (Khinya) Left Lateral 65 Wrench

Folds 66

Satur Anticline 66

Datunda Anti;:line 67

Akoda Syncline 68

Motipura Anticline 58

Gudha Syncline 69

Chapter V PHOTOG£OirHYSICS 70

General Statement 70

Methodology 71

Data Generation 71

Analytical Treatment of 71 Lineaments

Trenu Analysis of Lineaments 7.3

Lineament Intersect i or? Density 75

Trend 6urtace Analysis of 78 Lini ament Intersection L/cnsity

Lineament Incidence Analy. is 80

Trend surface Analysis of 82 Lineament Incidence Density

Joncurrenct And Synthesis 84

Axial Trace Geometry 84

Lineament Geometry 85

Trend Analysis 85

Lineament Intersection 86

Lineament Incidence 87

Structural Evolution of the 90 Area

Source and Environment of 90 stresses

Tectonic Styles and Structural 91 Fabric

Brittle Failure 92

Joints (J & J ) 93

The Great Boundary Fault (F^) 93

Wrenches (F„) 95

Chapter VI SUMMARY AND COi-rcLUSION 97

REFERENCES 103

( i )

LIST OF TABLE5

Table-I Generalised lithostratigraphy of 5 Vlndhyan Supergroup in southeastern Rajasthan

Table-II Pnoto-characters of Vindhyan 36 sedimentaries in Bundi area. Raj as than.

Table-Ill Axiai trace orientation of major folds 85

Table-IV Carninal lineament trends which 86 exhibit general geometrical relation­ship with the stress trajectories

Table-V Orientation ot lineament intersection 88 density and trend surface maxima

Table-VI Orientation of lineament incidence 89 den-sity and trend surface maxima

Table-VII Orientation of joint sets 93

( i i )

LIST OF FIGURn,i

F i g u r e - 1 Index map 2

F i g u r e - 2 A Geomorphological map ot Bundi 9

a r e a , Ra jas than

F igure -2 B Charnbal d r a i n a g e system 18

F igu re -3 Drainage p a t t e r n s 20 F i g u r e - 4 P r o f i l e s a c r o s s t h e a rea showing 2 3

p l a n e r s u r f a c e s or Vindhyans, Bhi lwaras and Charnbal a l luvium

F i g u r e - 5 Geo log ica l map of Bundi a r e a , 30 Ra ja s than

Figure-6 Tectonic map 55

Figure-7 Lineaments of Bundi area, 72 Rajasthan

Figure-8 Azimuthal orientation of 74 lineaments in Bu::ai area, Rajasthan

Figure-9 Lineament intersection density 76 distribution in Vindhyan terrain, Bundi area, Rajasthan

Figure-10 Lineament intersection density 77 contour map

Figure-11 Lineament inters"et;1:ion trend 79 surface map

Figure-12 Lineament incidence density 81 contour map

Figure-13 Lineament incidence trend 83 surface map

Figure-14 i^ynoptic schematic diagram 94 showing stress distribution and accompanying finite strain in a cratonic regime, Bundi area, Rajasthan,

( iii )

LIST OF PLATES

Plate-1 Fig. 1 : General view of cuesta 12 in Upper Rewa Sandstone and gully erosion in Jhiri Shale below Bundi fort. Bundi town in foreground

Fig, 2 : Steep cuesta in Upper Rewa Sandstone, Location : 3 Kms. northeast of Bundi

Plate-2 Fig. i: Scarp of Lower Bhander Sandstone 14 showing caverns along bedding planes. Location: 1 Km. east of Khatkar along bank of Mej river

Fig. 2 : Gully erosion in Jhiri Shale Location : Bundi fort

Plate-3 Fig. 1; Current ripple marks in Jhiri 45 Shale, Location : 2 Kms. northwest of Bundi

Fig. 2; Oscillation ripple marks in Jhiri Shale , Location ; 2 Kms. northwest of Bundi

^'ig, 3 : Solution pits in Bhander Limestone, Location : 5 Kms. northwest of Bundi.

Plate-4 Fig. 1: Asynmetric anticline in 59 Bhilwara Phyllite, Location ; North of Thikarda

Fig. 2 : Asymmetric non-plane, non-cylindrical anticline in Samaria Shale along Bundi-Satur fault zone. Location: 6 Kms. northwest of Bundi.

(,W)

PREAMBLE

The dissertation embodies the geological investigat­

ions of the Vindhyan Supergroup in parts of Bundi district,

Rajasthan based on remotely sensed data fran spaceborne raul-

tispectral scanners and airborne photographic camera. The

study was directed to integrate photo-recognition elements

for synthesis of geology and geomorphology of the area and

its subsequent authentication by selective field checks.

Photogepphysical studies were carried out £or interpreting

stress environment of the Vindhyan Supergroup, ,cr trajectories

were interpreted through lineament intersection, incidence

and orientation analysis. The present study was undertaken

iu part fiilfilroent for the award of degree of M.Phil in

Geology of Aligarh Muslim University, Aligarh.

Chapter I

INTRODUCTION

General Statement

The great Vindhyan Basin located in the north central

India is one of the largest cratonic basins in India encom­

passing an area of about 1,66,400 sq. kms. (Fig. 1). The

Vindhyan sediments extend from Dehri-on-Son in Bihar through

Rewa, Panna and Sagar ixito Chittorgarh - Dholpxir tract in

Raj asthan fringing the Archaean massif of Bundelkhand craton*

The subcrops of ViiKihy ii sediroentaries have been recorded

between Agra and Allahabad northeast of Bundelkhand massif

roughly along the Yamuna lineament. The Vindhyan Basin is

a large intracratonic negative structure with its axis alig­

ned in ENE-WSW direction* The geometry of the Vindhyan Basin

appears to be tectonically controlled by major crustal grains

which are endogenic, in the northwest, the Great Boxindary

Fault of Rajasthan controls the structviral architecture

between Chittorgarh and Agra, in southwest, the basin con-

figxiration has been controlled by the Narmada-Son line. The

north eastern fringe o£ the basin appears to have been con­

trolled by the WNW-ESSE trending lineament exogenically

1

3

expressed as Yamuna lineament between Agra and Allahabad.

The study area is located close to the north western

basinal fringe and shows intense tectonic deformation. The

structural conplexities in the area have introduced an ele­

ment of uncertainity in regional stratigraphic correlation

(Coulson, 1927; Heron, 1953; Prasad, 1984). Multilevel

remotely sensed data was analysed and integrated to obtain

synoptic view for interpretation of lithcstratigraphy and

to carry forward the lithological and structiiral units for

inteirpreting the lithcstratigraphy of structurally deformed

peri-basinal segment of the Vindhyan sediroentaries in the

Bundi area.

Location and Extent of ttoe Area

The study area falls between north latitudes 25^18'47"

to 25°43»34'" and east longitudes 75°21'36" to 76°5'0" cover­

ing about 2,800 sq. kms. It forms parts of Btindi district,

Rajasthan and is included in Survey of India toposheet nos.

45 Oand 45 C.

Previous Work - A Brief Review

Medlicot (1859) was the first to start regional geo­

logical mapping in Vindhyan basin. Subsequent work was car­

ried out by Mallet (1869), Oldham (1093), Vr^slgnburg (1906)

and Auden (1933). Coulson (1927) and Heion (1953) have

given a detailed account of the geology of Central Rajputana

and classified the Vindhyans into Kaimiir, Rewa and Bhander

rocks. However, a controversy arose between their mapping

since Heron mapped the upper horizons of Bhander Subgroup

as Sirbu Shales and Upper Bhander Sandstone between Chittor-

garh and Kota. whereas between Indergarh and Bundi, Coulson

mapped the same as Samaria Shale and Lower Bhander Sandstone

overlying Bhander Limestone. Prasad . (, 1984) have

followed the broad classification given by Coulson. Prasad

and Sharma (1977) described the geometry of Great Boundary

Fault of Rajasthan and Iqbaluddin et al. (1978) discussed the

genesis of the Great Boundary Fault of Rajasthan under a cen­

trifugal stress model. Prasad (1984) has carried out the re-

visional iBB jping in parts of the Vindhyan basin in south-­

eastern Rajasthan. Table 1 presents the lithostratigraphy

of the Vindhyan Supergroup in south-eastern Rajasthan.

Table - I

GENERALISED LITHOSTRATIGRAPHY OP VINDHYAN SUPERGROUP IN SOUTH-EASTERN RAJASTHAN

(AFTER PRASAD, 1984)

Groups Formations

BHANDER (1215 m)

REWA (285 m)

KAIMUR (110 m)

KHORIP (475 m)

Dholpura (Upper Bhander) Shale Balwan (Upper Bhander) Limestone Halhar (Upper Bhander) Sandstone Sirbu Shale Bundi Hill (Lower Bhander) Sandctone Samaria Shale Lakheri (Lower Bhander) Limestone Ganurgarh Shale

Govindgarh (Upper Rewa) Sandstone Jhiri Shale Indargarh (lower Rewa) Sandstone Panna Shale with limestone intercalation

Akoda Mahadev (Kaimur) Sandstone Badanpur Conglomerate Qiittaur Port (Kairaur) Sandstone

Suket Shale with limestone intercalation Nimbahera Limestone Bari (Nimbahera) Shale Jiran Sandstone

LASRAWAN (272 m)

SAND (210 m)

SATOLA (835 m)

Binota Shale Kalmia Sandstone (Glauconitic)

Palri (Sawa) Shale Sawa Sandstone (Grits)

Bhagwanpxira Limestone (stromatolitic) Khardeola Sandstone (Grits) Khairmalia Andesites

-unoonf ormi ty-

Pre-Aravalli (Bhilwara) Supergroup of rocks.

n

Data Source

The different data inputs for the present study include

a total of 55 panchromatic aerial photographs, Landsat MSS

images of band 5 and 7 and Survey of India toposheets.

Methodology

The work was carried out in following steps:

i. Preparation of loose, uncontrolled mosaic of air photos and annotation of photographs, followed by a careful study to obtain a general idea about the geological and geomorphological set up of the area.

ii. Detailed stereoscopic examination of aerial photo­graphs on 1:63,000 scale,

iii. Transfer of interpreted data from aerial photo­graphs to a controlled base map.

iv. Collection of groxind truth and its incorporation in the photo interpreted map, preparation of various thematic maps.

V. Statistical approach to lineament analysis, Pre-paratixm of lineament map and domain wise linea­ment trend analysis in terms of percentile frequeiicy and percen-tile length,

vi. Preparation of lineament incidence density map and determination of mean structural trends.

vii. Preparation of lineament intersection density map and confutations of structural trends.

viii. Final isati on of plates and reports.

Acknowledgement

The studies have been conducted under the inspiring

gxiidance and valuable supervision of Dr. Iqbaluddin, professor

and Director, RSACREG, Aligarh Muslim University, Aligarh and

Professor A.K. Roy, Head, Geosciences Division, IIRS, Dehra

Dun . Mr. J.L. Ganju, Chief Geologist, KIMIPE, Dehra Dun

spared his valuable time for many fruitful sessions of dis­

cussion. Financial assistance was provided by CSIR, New Delhi.

Sincere thanks are extended to all.

H

Chapter II

GEOMORPHOLOGY OF THE AREA AND LANDSCAPE EVOLUTION

General statement

Geomorphological study of Bundi area has been carried

out in an attenpt to establish correlation between landforras

and geology of the area (Fig.2A) . Morphology and geometry

of the landforras have been evaluated through convergence of

photo recognition and geotechnical elements. Depending on

the spatial disposition and origin, the conponental georaor-

phic units have been mapped under stereo models on the basis

of homogeneity of tone, texture, drainage pattern, lithologi-

cal characters and structural fabric of the landforms.

Structural Hills of Bhilwaras

The Bhilwara roet^asediments, exposed north of the

Vindhyan strata, form ENE-WSW trending linear ridges. The

morphotectonics of these hills is determined by the dominant

planer tectonic anisotrophy BS2 which is parallel to s\ib-

parallel in strike with the bedding. The structxiral hills

have given xi.se to hogback topography due to steep dispxjsi-

tion of the plaa sr faijric that has controlled the landscape

s)^^f ' n'.::::::': r* "

Ill

evolution in the Bhilwara metasediments. Locally the quart-

zite bands form clusters of isolated hillocks in areas where

the Bhilwara rocks have produced conplex outcrop patterns due

to polyphase deformation (Iqbaluddin; 1984>,

This geomorphic unit is characterized by medium grey

tones, coarse texture, high resistance to erosion and exter­

nal, s\ib dendritic and sxib-paxallel drainage of low density.

Pediment of Bhilvaras

The Bhilwara pediment have been mapped in the area cut

north of Great Boundary Fault as low^ rocl^erosional surfaces

fringing the structural hills of Bhiiwaras, The softer meta­

sediments (schists and phyllites) occur almost without any

cover with a discordant relationship with the geomorphic

surface which is genetically an erosional sxirface and has

exhxjuned the various structural levels of the tectonically

deformed roetasedimentary cover of the Bhilwara Supergroup.

It is identified on aerial photographs by high grey

tone, coarse texture, rock look, absence of vegetation and

are characterised by subdendritic and angular drainage and

low erosive resistance.

11

Shallow Burled pediment of Bhilwaras

Fringing the pediment of Bhilwaras and occassionally

transgressing over it are shallow buried pediments which are

characterised by a thin veneer of reworked weathered mantle

which vary in thickness from few eras to about 5 m. The geo-

morphic surface is genetically a depositional surface and

in morphochconology is younger to the erosional surface of

the pediment of Bhilwaras with which it exhibits transgres-

sive relationship. This surface is a Quarternary depositio­

nal plane. The time gap between the erosional surface of the

Bhiiwara pediment and the depositional surface of the shallow

buried pediment is a question mark in the chronology of the

landscape evolution in the area.

On -the aerial photographs, the shallow buried pediment

is identified by light to medium grey tones and fine to roedixun

texture. It covers the large area and is characterized by

extensive agricultiiral land use. The biocover is mostly

thorny and bxishy. Surface drainage is poor and erosion is

dominantly by sheet wash.

Buried Pediment of Bhilwaras

The rock cut svirfaces with a more than 5 m thick cover

of reworked weathered material have been mapped in the area

as buried pediments. This georaorphic unit is characterized

]2

EXPLANATION TO PLATE - I

Figure-1 General view of cuesta in Upper

Rewa Sandstone and gully erosion

in Jhiri Shale below Bundi fort.

Bundi town in foreground.

Figure-2 Steep cuesta in Upper Rewa Sandstone,

Location - 3 Kms. northeast of Bundi

PLATE 1

Fig.l

Fig.2

13

by a depositional surface and is demarcated on air-photos

by dark grey tone, matty texture (due to human influence),

sinuous boundaries and extensive cultivation.Gully and

sheet erosion are extensive in the unit wherever it fringes

the Mej river.

Structural Hills of Vindhyans

The geomorphic architecture of the landscape in the

area is determined by the structural hills of Vindhyans

which stand out in prominent relief overlooking the buried

and shallow buried pediments of the Bhilwaras and their

accompanying stiructural hills. The structural fabric of

the Viadhyan sedimentaries has controlled the raorphotec-

tonics of this geomorphic unit. The WSW-ENE trending beds

of sandstone due to the differential weathering and high

erosive resistance have formed cuesta ridges which occur

as parallel to sxib-parallel elements. Theie strike ridges

show asyninetry of profile with gentle dip slope and steep

obsequent slopes. The cuestas have been delxoeated into

gentle and steep depending upon the local variations in

the amount of dip of the bedding surfaces. The gentle cues­

tas have dip of 3 to 8 and steep cuestas have dips nearing

25 to 30 . Sandstones- Kaimur Rewa and Bhander have given

rise to structural hills of Vindhyans in the study area

(PI. 1 Fig. 2 ) .

14

EXPLANATION TO PLATE -2

Figure-1 Scarp of Lower Bhander Sandstone

showing caverns along bedding planes.

Location - 1 Km, east of Khatkar

along bank of Mej river.

Figure-2 Gully erosion in Jhiri Shale

Location - Bundi fort.

PLATE 2

Fig. 2

],'»

Under stereo models, it is characterized by raedixim

grey photo tones, medixim to coarse texture, high erosive

resistance, paucity of human influence and thin to negligi­

ble surface cover. The drainage on the obsequent slope is

joint controlled and s\ib parallel. On the dip slopes, the

drainage channels exhibit sub-dendritic patterns. The dip

slopes are characterized by homogeneous tone and obsequent

slopes exhibit banded tones, uneven slopes and occassional

vegetal cover.

Structural Valleys of Vindhyans

The shale formations which occur at various strati-

graphic levels in Vindhyan Sv^ergroup as inter stratified

sequence with the sandstones, due to their low erosive

resistance have given rise to structxirally controlled ero-

sional valleys. These valleys are parallel to sub-parallel

in strike with the flanking structural hills of Vindhyans.

The general trend is controlled by the dominant structural

fabric which is WSW-ENE in the area. The valleys are asym­

metrical in profile- These valleys are occupied by drainage

channels which are entrenched.Lithologically the valley

floor is made of soft and friable lithologies viz. shale

and limestone bounded by cuesta and obsequent slopes of

sandstone ridges.

Ifi

These are distinguished on air-photos based on medium

grey tone, fine to inediiim texture and linear cultivation pat­

terns. Gully erosion is prominently displayed along the river

courses.

Talus and Scree Zone

West of Bundi a 2,5 km wide and 23kms long zone of

talxis and scree has been mapped with isolated fans. Locally

the fans coalesce to form talus zone. The fans have curved

distal margins and short rectilinear proximal margins. The

handles are missing in the fans suggesting that these have

evolved from a linear non-point source. The development of

fans has been possibly controlled by the receding front of

the structural hills of Vindhyans,

Under stereoraodels, the talus and scree zone is picked

up by high to medium tone, coarse texture, radial relief

and dichotomic drainage.

Alluvial Plains

To the south of Vindhyan hill range, a thick pile of

Chambal alluvixim is deposited on the Vindhyan pediment. The

thickness of alluvium cover varies from place to place. At

Silor and Matunda, the alluvial cover is very thin exposing

17

the Vindhyan strata. The alluvium consists of fine sand,

silt and clay.

Gully and sheet erosion is extensive along the river

courses. A zone of shallow ravines has developed along this

river. Under stereo models, gully erosion is picked up by

light tone, fine texture and pinnate drainage. Sheet erosion

is depicted in air photos by light tone, smooth texture and

absence of vegetal cover. These processes are accentuated

by neotectonic activity in Chairi al alluvium besides fine­

ness and less cohesive strength of soil cover.

Drainage Pattern

The area forms part of the caiandsal drainagpe system

(Pig,2B) . The drainage of the area is affected by Mej and

Kural sub basins.

tffij SUB-BASIN:

Mej river is the main artery of the drainage in the

noxthexn part of the study area. It is ephexoeral and is

seventh order drainage system. The Mej river originates

from the hills and the schistose country of the Bhilwara

Supergroup and the general pattern of drainage has been con­

trolled by the regional slope which is towards east to ESE.

CHAMBAL DRAINAGE SYSTEM

^^ TONK

0'

»*

BlWtH

SAWAI MADHOPUR

> .

FIG.2B 7 7 ^

^ < •c

25;

T

Ifl

It crosses the structural grain of Vindhyan sedimentaries

roughly in a N-S direction where local drainage anomalies

are seen manifested as rectangular drainage and linear

stretches of drainage channels. The morphotectonics of the

Mej river across the structural grain of Vindhyans is con­

trolled by a gravity fault. When it emerges from the struc­

tural hills of Vindhyans into the Chambal alluvium, its

trend is controlled by the regional slope. The first order

channels are controlled by the local structural planes

foliation, joint and bedding. The second order channels

follow lithological contacts and local slope. These have

variable orientations. The third order channels are short

rectilinear and generally entrenched which join Mej river

and its important tributaries. These are controlled by local

landscape and slope characteristics of the area.

The overall pattern is sub dendritic but towards the

proximal end of the drainage system angular, pinnate and

parallel drainage systems have been recorded under the stereo-

models .

In Bhilwara terrain, the joint pattern and foliation

have exercised a dominant control on the drainage pattern

and have given rise to angulate, sub-angulate and rectangular

drainage pattern depending on the angle of intersection of

joint plane with foliation plane. In Bhilwara phyllites, the

drainage density is high (Fig. 3A) wiiile In Bhilwara quartzites

20

? ^ us O S2 v> ^ o ? z < < OC t/)

o ^ cr ^ UJ 5 Q * . z = < :2 X O CQ z < ca h- UJ

y o a: _i

^ ^ \ f( \ rK / ^ V i I ^ "* ^ • \ V ^

V ^ ^ \::>^ ^ ^ \ \ c - --V V ^ \ ^ \ ^ \ ^ ^~"\ \ y ^ \ \ ^ ^ A ^ \ ^N^ \ J vl_J _^>xj5i^ V^^-^ V. V" ""vv

N / \ \ y '* V /

) ^ ^ V ^ ^^-^ wC^ / I \ J^

lo

/^. ) —"

21

the drainage is svib parallel and density is low (Fig. 3B) .

In VindhyAu terrain, the shales are characterised by

pinnate drainage of high density and show rills and gullies

(Fig. 3E). Vindhyan sandstone ridges show sub-parallel drai­

nage and coarse drainage texture (Fig. 3E). In Lower Bhander

Sandstone which form plateau with rolling dips, the drainage

is controlled by trend of axial trace and culmination and

depression axes and is rectangular (Fig. 3D). Bhander

Ldmestone show sub-dendritic drainage pattern e.g. in the

core of Satur anticline (Fig. 3C).

KURAL SUB BASIN:

The Kural Sub-basin represents sixth order drainage

system. It rises on the crest o^ the Vindhyans and drains

the area with a number of tributaries, notable

among them being Ghora Pachar, Mangli and Talera rivers.

The drainage system of this sxib-basin is determined by re­

gional slope which is Eiffi. The drainage upstream of its

confluence with Mej river is characterised by sinusity of

the drainage channel which is in geomorphic inhomogeneity

to the over all tectonic setting of the area. The Kural

drainage is entrenched and is cutting through its own flood

plain. The Kural drainage channel exhibits sinusity along

the main course but its first order channels are showing

gully erosion through headward developjaaent, which is

0')

indicative of rejuvenation of the drainage. The drainage

anomalies upstream of the Mej confluence possibly represent

morphotectonic signatures of a sub-surface structural dis­

continuity whose neotectonic rejuvenation possibly led to

compressed meanders and sinusity of the Kural drainage chan­

nel, in addition to a number of fluvial landforms like point

bars and cut-off meanders, in its distal reaches.

Planar Surfaces

In order to study the chronology of the landscape

evolution of the area, analysis of the planar surfaces was

attempted through superposition of profiles across the strnac-

tural grain of Vindhyan and Bhilwara Supergroup. Five sect­

ion lines wer« selected for preparation of profile sections

in order to reconstruct the levels of the planar surfaces

in the study area. The three planar surfaces Vindhyan,

Bhilwara and Chambal have been identified which roughly

correspond to 475 m, 260 m and 228 m elevations respectively

(Fig. 4).

VINDHYAN SURFACE:

The Vindhyan surface is characterized by the develop­

ment of a planar surface roughly corresponding to an eleva­

tion of 4 75 ra. It is the oldest surface in the area and is

O

CO UJ

u < LL

cr Z) CO cr <

o

E i n -n

> z>

< QD

^

c I CO

< LU cr <

UJ

J-

co CO o cr u <

CO LLI

_l Lu O QC a.

o

o 2 <

(O < cr <

_ j

X GQ

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>

' 4

morphologically expressed as Vindhyan plateau in the area.

Its surface expressions are depicted as accordant svumnits

of Vindhyan structural hills. The homogeneity of the Vindh­

yan surface is punctuated by isolated hills of Vindhyan sand­

stone. Subsecjuent to its development, it was subjected to

differential erosion, shale occupying the valleys and sand­

stones forming accordant summits.

Dynamically the surface appears to have been evolved

dorainantly by erosional process which has brought the diverse

lithologies of Vindhyan Supergroup corresponding to different

stratigraphic horizons approximately at the same geomorphic

level. The dating of the surface is difficult in the absence

of any well defined mariner horizon, however, it is suggested

that it will be a Palaeozoic or Mesozoic surface as it is

older to pre-Cretaceous Bhilwara surface.

BHILWARA SURFACE:

The pediment, shallow buried pediment and buried

pediments carved out of the Bhilwara Supergroup have been

smoolrhened out by regional process of erosion to an undulat­

ing surface, which in the regional context has been inter­

preted as the planar surface corresponding to an elevation

of 260 m and has been designated as the Bhilwara surface.

The homogeneity of the surface is locally punctuated by

isolated hills of hard and resistant Bhilwara quartz!tes.

The Bhilwara surface has evolved as a result of sheet

wash in Bhilwara plains. The spatial spread of the surface

has been controlled by the contrasting lithologies. The

Bhilwara quartzites and Vindhyan clastogenes resisted eros­

ion in the period that elapsed the generation of Vindhyan

surface. The Bhilwara phyllites being susceptible to mass

wasting processes led to the generation of Bhilwara surface

in the area north of Vindhyan terrain. As a rough approxi­

mation it is suggested that based on its relative elevation

to Vindhyan and Chambal surface it is younger than the Vin­

dhyan and older than the Chambal surface. Taking the region­

al tectonic setting of Rajasthan into consideration, it is

ventured that it is equivalent of pre-Cretaceous surface in

adjoining tract of Banswara (Iqbaluddin, 1985). This infe­

rence is based on the fatrt that the geomorphic surface is

physically continuing as accordant element from Gujarat

to southern Rajasthan. In Gujarat the Bagh beds of Creta­

ceous age occur within the surface at accordant levels with

the associated Proterozoic metamorphites. The spatial occu­

rrence of Bagh beds with the metamorphites and the extension

of surface as accordant geomorphic element into adjacent

tract of Rajasthan suggest genetic and temporal homogeneity

in evolution of the planar surface.

2n

CHAMBAL SURFACE:

The Chambal surface is represented by depositional

surface of Chambal alluvial plains and roughly corresponds

to an elevation of 228 m. The homogeneity of Chambal depo­

sitional surface is locally disturbed by rock cut surfaces

of Vindhyan pediments.

Dynamically the surface has developed as a result of

deposition of recent sediments by Chambal and its tributar­

ies. This surface is younger both to Vindhyan and Bhilwara

surfaces and is essentially a Quarternary depositional

surface.

Landscape Evolution

A model for the landscape evolution of the Bundi area

in Rajasthan has been evolved based on the study of various

geomorphic units in the area.

The geomorphic evolution of the area has been polycyclic.

The first geomorphic cycle in the area is represented by an

erosional phase which carved out the Vindhyan surface roughly

corresponding to an elevation of 475 m. It has brought the

structurally and lithologically inhomogeneous units of Vindh­

yan Supergroup approximately at the same level. In time, this

phase was accomplished somewhere during Palaeozoic or Meso-

zoic era.

2'1

The second cycle was initiated by sheet wash of Bhilwara

metamorphites. The Bhilwara phyleites yielded to onus of mass

wasting processes while Vindhyan sequence, being hard and re­

sistant, with stood it. The second cycle generated a planar

surface roughly corresponding to 260 m elevation characterised

by flat erased topography in the Bhilwara terrain.

The area south of the structural hills of the Vindhyans

was subjected to a cycle of erosion which continued after the

development of Bhilwara surface. The erosive cycle in the

area was restricted to the flood plain of the Chambal river.

The Chainbal during its youthful and mature stages carried out

erosion of the Bhilwara surface south of the structural hills

of Vindhyans, At a period possibly during Quarternary the

erosive cycle was punctuated and the Chambal stax-ted deposi­

ting fluvial sediments on the newly carved surface

roughly corresponding to 228 m. The depositional phase of

the Chambal generated a more or less homogeneous structure­

less plain which has been referred to as Chambal surface.

The lowering of base level of erosion led to rejuvenat­

ion of the ChairfDal drainage as a result of which it is cutt­

ing through its own flood plain resulting in the development

of bad land topography. The Chambal is an entrenched river

which is cutting through its flood plain.

Some of the tributaries of Chambal namely Kural river

are exhibiting cut off meanders, development o± river islands

28

and local braiding which are possibly taoirphotectonic signat­

ures of a major fault which is cutting across the Vindhyan

grain in Bundi sector.

^!) L.

Chapter III

PHOTOGEOLOGY

General Statement

The area between north latitudes 25°18'47" to 25°43'34"

and east longitudes 75°21'36" to 76°5'0" was studied under

stereomodels to evaluate the photogx^hic and geotechnical

characters, Thir-teen lithologic units have been identified

through convergence of spectral signatures and spatial dis­

tribution. These units have been correlated with standard

geological nomenclature established in the region through

concurrence with external information and local ground truth

(Fig. 5).

The area under investigation exposes rocks which are

referable to the Archaeans of Bhilwara Supergroup and the

sedimentary sequence of Vindhyan Supergroup. The alluvial

deposits have been assigned to Chambal alluvium of Quarter-

nary age. Table II presents the lithostratigraphic success­

ion and photocharacters of the litho units.

: /^M \

sQaiaBBBSia^iQ IM13III t- dnOkOMKt t(»*HOtll» •'"^tVlA'Wl

I I M i l

?)1

Bhllwara Supergroup

The metasedimentary sequence comprising phyllites,

schists, metagreywackes, quartzites, which have been sub­

jected to polyphase deformation and metaraorphism/ have

been assigned to Bhilwara Group of Archaean age (See Raja

Rao et al.,1971). The revisional mapping and synthesis

carried out by the Geological Survey of India has assigned

the Bhilwara Group the status of a Supergroup. The rocks

exposed in the area have been included under the Hindoli

Group (See Anon., 1981).

HINDOLI GROUP:

The sequence of shales, slates, phyllites^ mica schists

with interstratif ied sequence of inetagreywacke, raetavolcanic

quartzite, dolomite etc. representing green schist facies

metamorphism initially assigned to Aravalli system by Heron

(1936) and as Gwalior series by Coulson (1927) and as Jahaz-

pur and Pxir formations of the Bhilwara Group (Raja Rao, 1976)

have been assigned to Hindoli Group of the Bhilwara Super­

group (Anon., 1981).

Photogeologically, the rocks of the Hindoli Group

have been delineated into two lithounits namely pelitic

metasediments and quairtzites.

I U

Pelltlc Metasedlnvents;

The metasedimentary sequence of the Hindoli Group

divisible into various lithounits, under stereoraodels does

not provide any characteristic signatures for phyllite,

chlorite schist^ metagreywacke and slates. For purpose of

mapping, the entire assemblage of phyllitic metasediments

together with intercalations of metagreywacke have been

included under a loose term pelitic metasediments. The

horizon represents the oldest sequence best exposed bet­

ween Khinya in the south east and the Karwar in the north­

west. They form low hilly undulating topography and, at

places, short strike ridges which are picked up under

stereomodels as photo trends.

The litho unit is c±iaracterized by medium to dark

grey tones, coarse photo texture, dendritic and angulate

drainage with high drainage density. The resistance to

erosion is low. The gxound checks carried out between

Satur and east: of Akoda exhibit a sequence of shales, slates

and phyllite with intercalations of qxiartzite. The phyl-

lites are buff and reddish brown in weathered out crops.

Fresh exposuires are generally green. The phyllites are

chloritic, slates and shales are micaceous, sericite

being prominent along the planes of fissility. Bedding

plane inhcxnogeneities have been recorded from the shale

sequence near Akoda, where ripple marks are present as

:v,]

interference ripples.

The metasedimentary sequence of Hindoli Group in

the study area has been subjected to polyphase deformation.

The first folds are tight and isoclinal with the strike of

the regional foliation trending NE-SW. Foliation dips at

moderate to steep angles (50 to 65 towards northwest),

The axial plane foliation of tight to isoclinally folded

sequence forms the regional foliation which in the region­

al tectonic chronology has been referred as BS-. This fo­

liation has been folded into open folds trending northwest-

southeast. These folds are steeply inclined and moderately

plunging, in the local tectonochronology these have been

described as the second folds of the area.

QuartzitesJ

The stjcuctural hills occuring to the north of the

Great Boundary Fault and conprising coarse, purple coloured

hard quartzite criss crossed by veinlets of quarts have

been included in the Hindoli Group. On the basis of its

structural setting with reference to the Vindhyan sedimen-

taries, the quartzite occurs as steeply dipping ridges and

abuts against the Vindhyan sedimentaries. The tectonic plane

which separates the quartzite from the Vindhyan in the south

has been mapped as the Great Boundary Fault of Raj asthan.

.14

The quartzite outcrop have been more or less persistantly

mapped upto Akoda beyond which they are significantly absent,

The paucity of the ridge forming units west of Nayagaon pos­

sibly represents pinching of the sedimentary sequence.

Under stereomodels, the quartzite exhibits medixim

grey photo tones, coarse photo texture, external drainage

with svib-parallel pattern and low drainage density. The

erosional resistance is high. The unit forms hogback ridges.

Vegetation and soil cover are scantly. Human influence is

absent.

Quartz Reefs;

Quartz reefs occur as hogback ridges of symmetrical

profile north of Bundi, northeast of Khinya and west of

Akoda.

The reefs follow east west to ENE-WSW trend. These

are white in colour, weakly pegmatitic, very hard and re-

crys tal T1 fif^ri,

These exhibit light photo tones, uneven photo texture,

high erosive resistance and are chauracterized by absence of

surficial cover^both soil and vegetation. Tonal patterns

are homogeneous. The disposition of the reef is linear.

The linear pattern and their proximity to Bhilwara-Vindh-

yan bouadairsf suggest of the structural control in their

:]n

errtplacement t e c ton i c s along the Great Boundary Fau l t ,

Vindhyan Supergroup

The terrigenous elastics deposited in an inland crato-

nic basin representing an alternating sequence of shale and

sandstone with local intercalations of limestone and basal

sequence of andesitic volcanics have been assigned to Vin­

dhyan Supergroup. These rocks exhibit little or no meta-

morphism and peri-basinal deformation. Based on lithologi-

cal homogeneity, local relationship of superposition and

predominance of sandstone, shale and limestone sequences

the Vindhyan Supergroup has been sub-divided into Lower

and Upper Vindhyans. In the study area the sequence refer­

able to the Upper Vindhyans has been mapped. Their photo-

characters and geotechnical features together with select­

ive ground trxith have been presented and synopsis of the

recognition elements have been given in the table II.

KAIMUR GROUP:

An assemblage of sandstone with subordinate shale

flagstone and porcellanite overlying the Semri Group in

Son valley and coeval sequence in Rajasthan and Madhya

Pradesh has been designated as the Kaimur Group after the

Kaimur ranges where the sandstone form prominent scarps.

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The Kaimurs exhibit transgressive relationship with the

basement rocks e.g. Bijawars, Gwaliors and Bhilwaras. In

Rajasthan, the Kaimur Group have been delineated into

Chittaur Fort Sandstone, Badanpur conglomerate and Akoda

Mahadev Sandstone (See Presad, 1984). In the present study

the better known term Kaimur Sandstone has been used as

the stratigraphic separation of the Chittaur Fort and

Akoda Mahadev Sandstone in time sequence is subject of

debate.

In the study area, the Kaimtor Group is represented

by sandstone horizon with intercalation of conglomerate.

The sandstone has been designated as Akoda Mahadev Sand­

stone (See Prasad, 1984).

Kaimur Sandstone

The Kaimur Sandstone forms the oldest unit of the

Vindhyans in the study area. It rests with a first order

erosional unconformity over the pelitic metasediments of

the Hindoli Group. The Kaimur Sandstone outcrop have

been txaced more or less continuously from Antarda in

the east/Akoda where the sandstone outcrop broadens into

the closure of the Akoda syncline.

This unit shows lighter photo tones and uneven photo

texture. The outcrop density of this unit is high. The

40

bedding is prominent and joints are present as transverse

and longitudinal sets expressed as photo linears. It has

external, coarse, dendritic drainage. Resistance to erosion

is high. The surficial cover is thin and vegetation is ex­

hibited as random growth of flora.

This unit comprises two sandstone horizons separated

by a bed of conglomerate. The sandstone unit resting un-

conformably over the eroded phyllites is grey and buff in

colour, medium to coarse grained, at places, gritty to

pebbly and has a thickness of about 20 m. It is conform­

ably overlain by a two meter thick bed of conglomerate over-

which upper sandstone is present. The upper sandstone is

buff to reddish brown in colour, fine to medium grained

and consists predominantly of quartz set in a siliceous

cement. At places, glauconite has been observed in the

sandstone. Surface inhomogeneities are present as ripple

marks. Internal organization is seen as cross-troughs,

herring bones and parting lineations. It has conformable

contact with overlying Panna Shale.

REWA GROXJP:

The alternating sequence of sandstone and shale con­

formably overlying the Kaimurs has been designated as the

Rewa Group, named after Rewa district in Madhya Pradesh.

41

The Rewa Group is succeeded by chemogenic and clastogenic

association of the Bhander Group.

In the study area, the Rewa Group is represented

by Panna Shale, Lower Rewa Sandstone, Jhiri Shale and

Upper Rewa Sandstone,

Panna Shale;

Succeeding the Kaimur Sandstone a shale horizon has

been mapped in the Akoda syncline. It is traceable more or

less as a parallel band to the Kaimur Sandstone in the north­

ern limb of Akoda syncline. In the southern limb, its conti­

nuity is lost beyond the closure of Akoda syncline where it

truncates against Satur-Talwas fault.

The reflectance characteristics of the Panna Shale

correspond to darker phototones. The photo-textural para­

meter for rock is fine. The drainage is external, pattern

is dendritic and density is low. The litho types exhibit

low resistance to erosion, Morphotectonically the unit is

expressed as erosional valleys except in the closure of

Akoda syncline where it is exposed in the backslope of

Lower Rewa Sandstone, The bedding characteristics are not

clear where it occupies the erosional valleys. Surficial

cover is thick, vegetation is sparse and human influence

is expressed as cultivation patches. Outcrop density is low.

4 J

The rocks are greyish green in colour. The bedding

is well developed and is laminated to thinly bedded. It

consists dominantly of clay minerals with little quartz.

Its contact with the underlying Kaimur Sandstone is sharp

and with the overlying Lower Rewa Sandstone it is gradat-

ional. The superface and subface of the Panna Shale has

conformable relationship with the overlying and the under­

lying sequences and is represented by a 20 ra thick sequence

in the study area.

Lower Rewa Sandstone;

The Lower Rewa Sandstone occurs in the Akoda syncline.

It defines the inner arc of the synclinal structure. In the

area under study, it has been traced north of Bhaironpura

to east of Jetpura where it forms cuestas.

The litho-type is characterized by light to medium

phototones. The vegetation exhibits homogeneous light grey

phototones. Human influence is absent. Vegetation is expres­

sed as natural growth of dense jxingle. The corresponding

textural parameters for rock and vegetation are fine and

wooly respectively. The drainage is external, pattern is

dendritic and density is low. Erosional resistance is high,

Morphotectonically, it forms a zone of prominent cuesta

and escarpments. The bedding is clear in escarpments and

4:i

on cuesta slopes.

The Lower Rewa Sandstone is hard and compact, grey

to reddish brown in colour, medium grained, comprising pre­

dominantly of clastic quartz cemented by siliceous cement.

It approximates orthoquartzite in composition. Mega ripples

and cross-beds are common. The bedding is well developed

and is thinly bedded. The beds are characterized by uni­

formity of thickness and lateral persistence.

Jhiri Shale;

Jhiri Shale occurs more or less as a continuous hori­

zon to the north of Bundi-Indergarh fault where it occupies

the structural valley on the backslope of Upper Rewa Sand­

stone, Eastnorth east of Bhaironpura, the outcrops of

Jhiri Shale have been mapped in the Akoda syncline fring­

ing the outlier of the Upper Rewa Sandstone, In the southern

limb of the syncline, the Jhiri Shales abut against the Sirbu

Shale where they have been brought in juxtaposition by Satur-

Talwas fault.

On aerial photographs, it is distinguislied on the

basis of its medixim grey phototones, The photo textural

characteristic for the litho type is fine. The drainage is

external, pattern is dendritic in general and pinnate at

places with high drainage density. The resistance to erosion

44

is low. Human influence is expressed as cultivated patches

exhibiting darker phototones and matted photo texture. Bed­

ding is clear at many places. The outcrop density is low.

It occupies the strike valleys.

The Jhiri Shales are brick red in colour, splintary

in nature and fine grained. The unit is well cleaved and

well jointed. North of Bundi, numerous intercalations of

sandstone are present within the shale. About 1 )an north­

west of Bundi, symmetrical mega tipples (pl. 3 Fig. 1) and

asyrmnetrical ripple marks (Pl. 3 Fig. 2) have been preser­

ved in Jhiri Shale. It shows conformable relationship with

the underlying Lower Rewa Sandstone and the overlying Upper

Rewa Sandstone.

Upper Rewa Sandstone:

The Upper Rewa Sandstone forms the core of Akoda

syncline eastnortheast of Bhaixonpura and occurs as low

lying strike ridge northeast of Bundi.

Under stereomodels, it is characterized by light

to medi\am phototones and fijie to raexiium photo texture.

The drainage is external, pattern is sub-parallel and den­

sity is medium. Erosive resistance is high. Human influence

is absent and stratification is clear. The joints are trans­

verse and are manifested on air photos by sub-parallel

i^xtxANATi 'N ro i-'LAre -3

Fiyure-l Current rip- le mark; in Jtiiri oiielr:

Location- 2.Krn3. northwest of Bunai

Figi.'j:'r'-2 Oscillation ripple marks in Jhiri Shaie

Location - 2 Kms. northwest of Bundi

Figure-3 Solution pits in Bhanuer Li'TOStone

Location - 5 Kms, northwest of Bundi

PLATE 3

Fig.1

Fig.2

Fig. 3

4h

drainage. The outcrop density is high and the surficial

cover is thin. Morphotectonically the unit forms structu­

ral hills and plateau.

The rock is fine to medium grained and grey to buff

in colour. It is composed predominantly of quartz and lit­

tle feldspar with siliceous cement. The bedding is well

preserved. Surface inhomogeneities are present eis ripple

marks and trough and planer cross beds define internal or­

ganization. The Formation has attained a thickness of

around 30 ro.

BHANDER GROUP:

The dominantly chemogenic and clastogenic sequence

represented by sandstone, limestone and shale sequence rest­

ing over the Rewa Group has been included in the Bhander

Group, after the Bhander ranges in north of Narraada valley.

The sec[uence represents the upper most division of the Vin-

dhyan Supergroup. In the study area it is represented by

Ganurgarh Shale, Bhander Limestone, Samaria Shale, Lower

Bhander Sandstone and Sirbu Shales.

Ganurgarh Shale;

Resting conformably over the Upper Rewa Sandstone

along its dip slope a conformable sequence of argillaceous

4 7

rocks with arenaceous intercalations has been mapped as

Ganurgarh Shale from north of Bundi to east of Motipura.

Ganurgarh Shales also form the core of Satur anticline

where its outcrop pattern gives a clue to its possible

structural discordance with the overlying Bhandar Limestone.

It is concealed below the Chambal alluvium east of Bundi-

Satur wrench.

The litho-unit depicts medium phototones. The photc

textural pattern is fine. The drainage is external and

dendritic to subdendritic with medium to high drainage den­

sity. The unit is characterized by low resistance to ero­

sion. The human influence is expressed as cultivated pat­

ches and habitations. The cultivated patches are characte­

rized by darker phototones and matted photo texture while

habitations are picked up based on light grey tones and

uneven and blocky phototexture. The bedding expression

is poor under stereo models, Surficial material is thick

and outcrop density is very low, Morphotectonically the

unit occupies the strike valleys between the structural

hills.

The Ganurgarh Shale is reddish brown in colour,

fine grained, well bedded and well cleaved. It is made up

of clay and little quartz and contains nvimerous hard sandy

intercalations of about 5 cm thickness. Near Khatkar a

sandstone lense of several meters thickness has been recorded

•'r :^

in Ganurgarh Shale. The bedding locally exhibits ripple

marks and mud cracks and internal organisation as cross

beds .

Bhander Limestone

The Bhander Limestone is well exposed in the low

lying anticlinal cores of Satur and Datunda anticlines

where it forms an undulating topography due to numerous

folds and warps. To the east of Bundi, it runs continu­

ously upto east of Gaindoli and is repeated in the north

by the Bundi-Indergarh strike fault.

The Bhander Limestone exhibits high reflectance

which is manifested as light phototones. The photo texture

is fine to medium. Drainage is external and dendritic with

low drainage density. The resistance to erosion is medium.

Stratification is clear and boundaries are sharp. Surficial

material and vegetation is absent in inclined beds, in sub-

horizontally disposed layers, the human influence is expres­

sed as cultivated patches. The outcrop density is high.

The Bhander Limestone is grey to pink in colour/ fine

grained and well bedded. West of Khatkar, it is divisible

into three horizons the basal grey limestone, middle pink

and stromatolitic limestone and the upper grey limestone.

The prominent sedimentary structures include sun-cracks.

4!)

rain prints/solution pits (PI. 3 Fig. 3) and stylolites.

Warping is a common feoture in all the limestone

outcrops and it is perhaps, due to the competence contrast

of the sediments in the basin.

Samaria Shale:

The Samaria Shale occurs as a marker horizon and

invariably overlies the Bhander Limestone in the area.

The rock exhibits medium to dark phototones and fine

photo texture. The drainage is external and sub-parallel

with low drainage density. The resistance to erosion is

low. Bedding is poorly expressed. The boundaries towards

the base are gradational and the superface of the format­

ion has clear sharp contact. The surficial cover is thin

and the vegetation is sparse. Human influence is absent

except at Talwas where it is expressed as cultivated patches

and habitations. The outcrop density is high. Morphotectoni-

cally, the unit forms the backslope of cuestas,

Samaria Shale is green in colour, fine grained and

well bedded* It is mainly an argillaceous horizon with

limestone interbeds. Occassionally, Oolitic structures

are observed within the limestone. At places, intraformat-

ional breccia, composed of angular fragments of limestone

embedded in an argillaceous matrix, is seen at the contact

with Bhander Limestone. Bedding plane inhomogeneity is

locally seen as dessication cracks. The contacts of Samaria

Shale with the underlying Bhander Limestone and the overly­

ing Upper Bhander Sandstone are normal depositional ones.

Lower Bhander Sandstone:

In Khinya-Bundi sector capping the Samaria Shale

monolithic cover of sandstone is seen which defines the

form surface of Gudha syncline and Satur anticline. In

Bundi-Gaindoli sector it occupies a linear tract continu­

ously and reappears in the north due to Bundi-lndergarh

strike fault. It forms the form surface of Motipura

anticline near Talwas. This sandstone on the basis of

its local relationship of superposition has been assigned

to Lower Bhander Sandstone.

The litho-type exhibits light to medium photo-tones

and fine photo texture. The drainage is external and den­

dritic to parallel and rectangular in pattern with low

drainage density. The erosional resistance is high. Stra­

tification is clear and massive. The contacts are sharp

and persistant. Surficial cover is thin. Vegetation is

expressed by random growth of flora and human influence

is exhibited by deforestation. The outcrop density is very

high. Morphotectonically the unit is expressed as struc­

tural hills and plateau.

r^i

The Bhander Sandstone is light grey, buff and red

in colour, hard, compact, massive and medium to fine grai­

ned. It consists of rounded to subrounded grains of quartz

set in a siliceous and ferruginous^ matrix. Iron leachings

and dendrites attest the high concentration of iron in

the sandstone. Three sets of joints-bedding, strike and

cross-are prominently seen. Bedding plane inhomogeneities

are seen as ripple marks. Internal organisation is manif­

ested as cross-stratifications and herring bone structure.

Sirbu Shale;

Sirbu Shale has very low outcrop density and at

most of the places is covered by surficial cover. It oc­

cupies the strike valley east of Bhaironpura and is con­

cealed below Chambal alluvium west of Bundi-Satur fault.

The lithounit is identified under stereoscope on

the basis of medium to light phototone,

fine photo texture, external, dendritic drainage of medium

density and medium erosional resisl;ance. The human influ­

ence is expressed as cultivated pai:ches and habitations.

Bedding characters are obscured by surficial cover. Vege­

tation is luxurient and surficial cover is thick. Outcrop

dejnsity is very low, Morphotectonically it forms erosional

valley east of Bhaironpura and Vindhyan pediment in the

.1 u

south. The shale and limestone are associated in such a

way that it is difficult to separate each other. The shale

is grey whereas the limestone is greenish grey to buff in

colour, argillaceous to arenaceous type and stroir.atolitic,

at places. Geodes have also been noticed:

QUATERNARY DEPOSITS:

Alluvium:

The area south of Bundi is covered by alluvial

cover of varying thickness. A narrow piedmont zone dem­

arcates the boundary between Vindhyan strata and alluvial

plain.

The alluvial beds are characterized by light to

medium tones depending upon moisture conditions. The allu-

viuni exhibits fine texture and mainly external, dendritic/

pinnate drainage of medium density. Extensive gully ero­

sion has given rise to the development of badland topography

mainly along Mej river. The other landforms include mean­

dering channel, cut-off meanders, channel islands and bar

deposits etc. The alluvium comprises fine sand, silt and

clay as it is deposited by rivers and streams emerging

from Vindhyan ranges. It has fairly good potential for

groundwater. The water table is shallow to moderate and

S.]

water is mostly potable.

The alluvial beds overlie the Vindhyan sequence with

an unconformable junction.

54

Chapter IV

STRUCTURE

General Statement

The area can be delineated into two tectonic systems

on the basis of tectonic styles and chronology of the tect­

onic and depositional elements (Fig. 6). Stratigraphically

the rocks of the Archaean basement have been assigned to

Bhilwara Supergroup (Ann., 1981). The sedimentary cover

of the Vindhyan supracrustals has been assigned to Upper

Proterozoic (Prasad, 1984). The structural fabric asso­

ciated with the Bhilwara Supergroup has been included into

the Bhilwara tectonic system and that of the Vindhyan Super­

group into the Vindhyan tectonic system.

Bhilwara Tectonic System

The structural elements which have been picked up from

stereomodels and through selective ground checks in the

rocks of Bhilwara Supergroup comprise foliation, joints,

faults and folds.

f > T)

sn

FOLIATION:

The foliation is the most pervasive and penetrative

fabric element in the Bhilwara tectonic system. It is deve­

loped as indiscrete planes of mechanical inhomoyeneity gene­

rally trending ENE-WSW. The morphotectonic expressions of

the foliation planes are short strike ridges, linear

stretches of drainage channels, linear photo tones and

OGcassionally linear vegetation patterns have been recorded

from the Bhilwara tectonic system which correspond to the

ENE-WSW structural trends of the regional foliation.

The regional foliation in the tectono-chronological

sequence is referable to BS^ (Ann., 1981). The foliation

is of axial plane type and exhibit north-north-westerly

subvertical deps. The planar tectonic anisotropy is defined

by the preferred orientation of the sheet minerals-sericite,

muscovite and biotite.

JOINTS:

The joints have been picked as mlcrolinea ments

in the quartzites of the Bhilwaxa Supergroup. In phyliites

the morphotectonic expressions of the joints are not very

clear. Ground truth collection carried out in the area

reflects two distinct patterns of joints namely NW-SE and

N-S trending joint sets.

>7

These appear to be shear fractures which tectonically

correspond to the NNW-SSE cr, trajectory of the Bhilwara

tectonic system.

FAULTS:

The faults occur as idiomorphic elements in the

Bhilwara rocks. These are not very conspicuous in the

study area. Under stereomodels, the faults have been

interpreted in the Bhilwara metasediments on the basis of

disposition of quartz reefs. The tectonochronology of

the fractures is difficult to establish, however, for

purpose of description the faults in the rocks of Bhil­

wara Supergroup which are morphotectonically expressed

by quartz reefs have been considered as older than Vindh-

yan. The ground check carried out for these fractures at

a location 5 kms north-east of Jaitpur reveals the fault

is a strike slip failure which has off-set the bedding

and ttie foliation trends.

POICS:

Major folds are not discernible under stereomodels

in the rocks of Bhilwara tectonic system. Ground checks

reveal two distinct styles of folding in the phyllitic

roiCks of the area. The dominant fold style is represented

by N60E-S60W trending tight to isoclinal folds which are

moderately plunging and steeply inclined. These folds in

regional tectonochronology can be assigned to BF2 (Ann.,

1981) as BS- = BS has acted as a fault surface for these

tight to isoclinal folds. The area has been subjected to

superimposed deformation. The superiitposed folds are open

and symmetrical. Locally overturning of the limbs have

been recorded. These folds are steeply plunging and

steeply inclined. The axial trace trends N50W-S50W.

South of Akoda, tight folding has been recorded in the

vicinity of the Great Boundary Fault, The axial trends

of these folds roughly coincide the structure of Vindhyan

sedimentaries trending ENE-WSW (Pi.4^ Fig, 1). The inten­

sity of tightness decreases northwards from the trace of

Great Boundary Fault. The development of these folds is

enigmatic, possibly they may belong to the fault tectonics

associated with the genesis of the Great Boundary Fault.

Vindhyan Tectonic System

The structural elements of Vindhyan tectonic sysi;em

have been picked up from detailed study of aerial photo­

graphs and through selective field checks. The major struc «

tures are elaborated below:

^XPL/uNATIOM TC PI,ATE - 4

F i g u r e - 1 A s y m r n e t r i ' - a n t i c l i n e i n

B h i i w a r a P h y l l i t e

L : c a t i o n - N o r t h of i h i k a r d a

F i g u r e - 2 A p y m . n e r r i c n o n - p l a n e ,

n o n - c y l i n d r i c a l a n t i c l i n e

i n 3 a m a r i a oh ; l e a l o n g B u n d i -

S a t u r i a u l t z o n e .

L c a t l ; n - 6 K m . . northv. '^L-1 o f Bunv.i

PLATE A

Fig.1

no

FAULTS:

in the area under study the Great Boundary Fault of

Rajasthan has been traced as a major structural grain from

Antarda in the east to Khinya in west. More or less, para­

llel to sub-parallel to the structural grain of the Great

Boundary Fault, two other strike faults have been mapped

which for ease of description have been designated as Satur-

Talwas fault and Bundi-lndergarh fault. The geometry of the

Great Boundary Fault and its cotectonic grains has been

punctuated by secondary wrench faults prominent among

which are:

Thikarda right lateral wrench

Bundi-Satur r^ht lateral wrench

Datunda left lateral Wrench

Ruppura left lateral wrench

Gxeat Boundary Fault:

The Great Boundary Fault in the study area has been

mapped on the northern fringe of the Vindhyan Basin. It

has been traced from Antarda to Khinya. The surface mani­

festations of the fault have been erased due to deep weath­

ering and erosion which the rocks of the area were subjected

to during the polycyclic landscape evolution.

8 1

The termination of the various lithological units

of the Vindhyan Supergroup against the phyllites and schists

of the Bhilwara Supergroup support the interpretation of the

lithoboundary of the Vindhyans and Bhilwaras as a tectonic

plane. The failure plane itself has not been observed in

the study area but manifestations of the fault related

strain have been recorded from the peribasinal lithotec-

tonic units which occur as sliver between the Great Bound­

ary Fault and its syntectic element Satur-Talwas strike

fault. The strain is manifested by steepening of the

dips in the proximity of the Great Boundary Fault. Develop­

ment of tight folds locally recumbent (e.g. south-east of

Akoda) has been recorded from the vicinity of the Great

Boundary Fault. The throw of the fault has been variously

interpreted as 1500 m (Coulson, 1927; Heron, 1936) and 500m

(Prasad and Sharma, 1977) . In the study area, it is diffi­

cult to determine the stratigraphic throw of the Great

Boundary Fault. Around Akoda it has brought the Kaimur

sandstone to juxtapose against the Bhilwara phyllites and

quartzites, whereas in Satur-Khinya sector the lower Bhan-

der Sandstone has been brought to ab' ut against the Bhilwara

metasediments. The continuity of the fault between Thikarda

and Bundi-Satur wrenches has been punctuated, it has possibly

been eroded out alongwith the Vindhyans in the Barodia horst

block. The earlier mapping has placed the Great Boundary

f;;^

Fault as a tectonic plane between the Kaimurs and Bhanders

(Prasad, 1984). The current mapping carried out through

synoptic overview of the Landsat and aerial photographic

data support placement of the Great Boundary Fault on the

northern limit of the Kaimur Sandstone. The emplacement

of the quartz reefs colinearly with the grain of the Great

Boundary Fault has been interpreted as manifestation of the

fault zone representing the Great Boundary Fault. The Vindh-

yan rocks 1 Km south east of Akoda exhibit folding in the

proximity of the Great Boundary Fault. The folds exhibit

progressive tightening and overturning towards the basin

margin (The Great Boundary Fault), Farooqui (1987) has

recorded Great Boundary Fault as a thrust. The present

observation corroborate the inference recorded by Farooqui.

Satur-Talwas Strike Fault

The Satur-Talwas Fault occurs as siib-parallel element

of the Great Boundary Fault. The Great Boundary Fault bifur­

cates into two - one segiaant going towards Akoda and the

other towards Thikaxda. The surface manifestations of

this fault are omission of stratigraphy and truncation of

Sirbu Shale and Lower Bhander Sandstone against Jhiri Shale

in the eastern part and against Kaimur sandstone in the Wes­

tern part of the fault segment. The throw of this fault has

been estimated as 900 m wJiich has been conputed on the basis

hA

of juxtaposition of Jhiri shale against the Sirbu Shale.

The strike slip component of the fault has been estimated

as about 6 Kjis based on the strike separation of the Lower

Bhander Sandstone in Pipaliya sector.

In the vicinity of the failure plane, ferruginisation

has been recorded near Bhaironpura, Locally the ironoxide

has been mined as low grade ore in the area as evident by

the inclines enplaced along the strike of the fault,

Bundi-lndergarh Fault;

Bundi-indergarh fault extends from 1 km west of Bundi

following the ENE-WSW strike of the beds and continues upto

Indergarh in the east. This strike fault has been mapped as

a tectonic boundary between the Lower Bhander Sandstone and

the Jhiri Shale. Exogenically the fault is manifested by

repetition of stratigraphy, south of the fault plane. The

throw of the fault has been estimated as 1400 m. The strain

generally associated at the fault cont acts has not been

recorded along this tectonic plane. It is possible that

this fault is a thrust which has brought the Bhander sequ­

ence over the Jhiri Shale.

Thikarda Right Lateral VJrench;

The Thikarda right lateral wrench is developed as a

tectonic grain trending NN\ -S£E. It truncates the Great

R •;

Boundary Fault, Satur-Talwas fault and Bundi-indergarh

fault. The development of the wrench is possibly related

to the secondary faulting that has dislocated the struct­

ural trends in the Bundi area. It is developed as anti­

thetic element to Bundi-Satur wrench and forms the eastern

limit of the Barodiya horst. - The strike slip

component is not very pronounced. The dip slip conponent

appears to be the dominant character of this element. The

movement along the fault has been under a rotational dextr al

shear.

Bundi-Satur Right Lateral Wrench;

The Bundi-Satur right lateral wrench trends WNW-ESE

and truncates the Great Boundary Fault and its cotectonic

grain Satur Talwas and Bundi-indergarh fault. The Wrench

is possibly related to the secondary faulting and delimits

the Barodiya horst to the west. It brings Samaria Snale and

Lower Bhander Sandstone in juxtaposition with Bhander Lime­

stone in northern sector and upper Rewa Sandstone against

Ganurgarh Shale and Bhander Limestone north of Btmdi and

Ganurgarh Shale against Sirbu Shale in the south. This

relationship suggests the rotational movement along this

line under a dextral shear. Locally sheeting has been

recorded parallel to the fault with slickensides (iqbaluddin,

et al., 1978).

Datunda Left Lateral Wrench;

The continuity of the Great Boundary Fault has been

punctuated near Datunda by the left lateral wrench. It has

changed the Great Boundary Fault into a composite surface.

The manifestations of the wrench are lateral shift in the

Lower Bhander Sandstone and acute angle relationship of

the axial trace of doubly plunging Datunda anticline.

The fault has brought about a change in structural trend

of the trace of the Great Boundary Fault which is ENE-WSW

to the east of wrench and NE-SW west of the wrench.

Ruppura (Khinya) Left Lateral Wrench:

At Ruppura, the Great Boundairy Fault shows lateral

offset along the secondary wrench fault. This wrench trends

NE-SW and is manifested as about 20 m high scarp overlooking

the plain country to the south-west. The fault zone is cha­

racterized by closespaced joints occuring parallel to the

fault plane. The failure plane is exogenically expressed

by Lower Bhander Sandstone which exhibits differential re-

crystallisation in a 4-5 m thick fracture zone (Prasad, 1976) .

The fracture zone is characterized by extensive ferruginisa-

tion due to percolation of iron solutions along open fractures,

r;t ,

FOLDS:

The structural hills of the Vindhyans comprising

the Kaimur, Rewa and Bhander sandstones are folded into

a nximber of anticlines and synclines following the ENE-WSW

grain of the Great Boundary Fault. The major architectural

pattern of the area is determined by the sandstone horizons

of Kaimur, Rewa and Lower Bhander Sandstones, Major folds

picked up under stereomodels have been designated as:

Satur anticline and its complimentary syncline

Akoda syncline

Motipura anticline and its complimentary syncline.

Satur Anticline;

Satur anticline is a large, NE-SW trending, open to

gentle fold. The Lower Bhander Sandstone acts'as the form

surface which defines the geometry of the Satur anticline.

The hinge zone of the anticline has been folded into dinpie

folds which as a result of erosion have given rise to a

rectangular inlier of Bhander Limestone.

The Bhander Limestone exposed in the hinge zone of

Satur anticline exhibit mesoscopic folds which are in struc­

tural harmony with the major structures. These folds appear

to have been formed early in the deformational history and

(r?

represent low wave length structure. The folds in the

hinge zone are generally syaimetric and have open geometry.

Towards the limbs of the Satur anticline, the folds in

Bhander Limestone become slightly tight and asymmetric due

to shear that operated at the layer boundary between litho-

logies of contrasting hydropiastic behaviour. The northern

limb of the Satur anticline is truncated by the trace of

Great Boundary Fault. Towards east, the Satur anticline

is limited by a left lateral wrench fault.

Datunda Anticline;

It is exposed as a doubly plunging anticline. The

geometry of the anticline is defined by a band of Samaria

Shale which fringes the Bhander Limestone occuring in the

core of the anticline. The structure has been picked up

from the stereomodel studies. The plunge reversal has

been interpreted on the basis of double closure and elongate

outcrop pattern of the Bhander Limestone inlier in the core

of the structure. The axial trace of the Datunda anticline

roughly follows the NE-SW structural fabric of the Satur

anticline. Towards the south-eastern closure, the grain

of the Great Boundary Fault cuts across the structural

trend at acute angle.

r,s

Akoda Syncline;

Akcxia syncline extends from Akoda in the west upto

Jaitpura in the east. The major outcrop pattern is defined

by the Kaimur Sandstone which formed the northern limb of

the syncline and is folded into a broad gentle closure

south of Akoda village. The southern limb of the synclinal

structure is faulted by Satur-Talwas fault. Its geometry is

defined by the Lower Bhander Sandstone Horizon . The hinge

zone of the Akoda syncline has complex outcrop pattern ex­

pressed by outlier of Upper Rewa Sandstone, The complexity

in the geometry of structure has developed due to NNW-SSE

trending culmination and depression axes across the trend

of the Akoda syncline. Tectonically, it occurs as a sliver

between the Great Boundary Fault and Satur-Talwas fault.

Motipura Anticline;

Motipxira anticline occurs as a compliinentary structure

to the Akoda syncline. The geometry of the structure is brought

out by a structural closure 1 km. west of Motipvira, The anti­

cline is gently plunging and steeply inclined. Towards the

eastern part of the structure, the beds open up and are

folded into dimple folds which form series of complimentary

anticlines and synclines maintaining parallelism with ENE-WSW

axial trace of the major structure. The beds exhibit gentle

dips of 5° to 10°. The tightening of the stiructure and

steepening of the dips has been recorded in the northern

part of the structure where in the proximity of the Great

Boundary Fault the tectonic signatures have been accentua­

ted due to accximulation of the stresses in the peripheral

part of the basin (Iqbaluddin et al., 1978; iqbaluddin,

1979) .

Gudha Syncline;

South of Satur anticline, its conplimentary syncline

has been picked up under stereoraodels with axial trace tren­

ding NE-SW passing through Gudha village. The geometry of

the structure has been worked out from the outcrop pattern

of the Lower Bhander Sandstone exposed towards the south­

western closure of the syncline (Not reproduced in the

map.). The northern limit of the structure possibly ter­

minates against the right lateral Bundi-Satur wrench.

Chapter V

PHOTOGEOPHYSICS

General Statement

Strain generated linear photo-faiDric was studied

under stereoroodels through statistical and photo-interpre­

tation techniques, photogeophysical techniques for analysis

of structural fabric have been atteitpted in selected areas

(Blanchet 1956; 57; Mollard 1957; Lattman 1958; Henderson

1960; Hamn 1964).

Photogeophysics deals with the methodical statisti­

cal analysis of linear features observed on aerial photo­

graphs and investigates statistical changes of variable

quantitative factors. These factors are length of indivi­

dual lineament, their bearing, lineament incidence, linea­

ment intersection incidence and the spacing between parallel

to sub-parallel lineaments.

The present study was directed to correlate the

results of lineament analysis with the field observations.

The integrated approach involving remotely sensed linea­

ment data and ground truth was extended to decipher the

stress regimes responsible for the present structural geo­

metry .

Methodology

Basic data on structural fabric were generated through

photogeological and photogeophysical interpretations of stereo-

models. Structural patterns and anomalies were obtained through

statistical treatment of fabric data. The patterns and ano­

malies were interpreted in terras of stress regimes through

correlation of the present state of finite strain in the

area.

Data Generation

Fracture patterns expressed as lineaments were identi­

fied under stereo-models through convergence of photo-recog­

nition and geotechnical element exhibited as changes in micro-

relief, local rectilinearity of drainage channels, local

linearity of vegetational patterns, linear tonal variation,

short strike ridges and linear photo-textures. The linea­

ments were recorded on the overlays (Fig. 7) and were sub­

jected to statistical rigour to obtain stress trajectories

in the area.

Analytical Treatment of Lineaments

The lineament data were subjected to analytical rigour

through statistical treatment. The approach imbibes analysis

by azimutnal trend distribution, intersection density and

incidence density in an attenpt to analyse and interpreter

trajectorieG in the Bundi area of the Vindhyan Basin.

TREND ANALYSIS OF LINEAMENTS

The lineaments were analysed statistically and domain-

wise circular ray diagrams at 10^ class interval? showing

percentile azimuthal distribution of lineaments in the upper

half and the corresponding cumulative length in the lower

half of the circle were prepared (Fig. 8). The lineament

azimuthal trends obtained through circular ray diagrams were

subjected to mathematical mean analysis to obtain cardinal

lineament directions. Conceptual kinematic model was confuted

from the cardinal directions. The basic assunption in this

analysis has been that the fracture pattern obtained from

stereo-models represents first order joints genetically re­

lated to stress regime operative in cratonic basins {Ali,

1982) .

The trend analysis of lineaments shows the following

distinctive patterns:

In Bhilwara terrain, the dominant azimuthal classes

lie within NlO^E - SlO°W to N40°W - S40°£ and N30°E - S30°W

to NldE-Sldvi, Mathematical means of the azimuthal classes

are N15 W-S15 E and N50°E-S50°W respectively which give

CO

o

z:

en t— 2

UJ 2 < LU 2

_ i

L L

O

z o

< t—

z LU

a: o _ i

< I f—

Z) ^ M <

Z

<

< —> <

< LU cc < a 2 3 00

Q; cn O

'— -4—'

tl) c - Q Q,

£ e 3 OJ

2 Q-

2 — — ; 3 ] ^ ^ ^

/ en d

a> " ^ - Q Oi

£ ^ =) 0) Z C L

A ^

^ ~ _—^^^—- ^

OJ

o 1 _ +-• CD C

J 3 <D

3 0) Z C L

1

1 1

^

UJ

1

1 ^

UJ

1 1

1 1 5

\

\ . O i

o -c "c * - - CD

cn t_) C i -O) C;

_ j Q -

;[] —

OJ

-«-J

-C c • • - ' Qj

CTl (_) C I -Oi Oi

_ i Q -

—

0 ;

a -» -C c

en ^_, C 1-(1) CD

_i a

<

<

CD

CO

2

< > X Q Z

>

o

" < LU

<

CO

2 < >-Q 2

>

m

2

< or Q:

-^ LU

<

< ^ _ i

— X CD

<

/ '!

,' • )

the orientation oi the cardincii iinedments of Bi.ilward

Supergroup.

The Vindhyan sub-area I shows two maxima falling in

between N20°W-S2O°E to N60°W-S60°E and N20°E-S2O'^W to

N80°£-S80°W. Mataematical means of the azimuthal classes

of Vindhyan sub-area I are N40°W-i340°E and N50°E-S50^W

which give the cardinal lineament trends of the area.

The Vindhyan sub-area II shows two maxima falling

in between NlO°E-S10*^W to N30°W-S30°E and N60°E-S60°W to

N80 E-S80 W. Mathematical means of the azimuthal classes

of Vindhyan sub-area II are NlS^W-SlS^E and N7o'^E-S70°W

respectively which represent the cardinal lineament trends

of Vindhyan sub_area II,

LINEAMENT INTERSECTION DENSITY

To obtain intersection density data, the area was

subdivided into 25 sq. km. cells. The cell boundaries are

so chosen that as far as possible, each cell should have

some value of intersection density (Fig. 9). The number

of lineament intersections per cell was plotted as cell

value in the central part of the cell. The area was con­

toured by extrapolation technique taking central cell

value as control. A lineament intersection density contour

map was thus prepared (Fig. 10). The contour maxima do not

o o LL

j

¥

LTt

f?, %

1

- -f-

Z < X

< <

< l i j

<

3 00

< - oc

1—

< >-n: o ^ >

^ z o »— CQ

»— l>0

o >-1— K/) z UJ

o z o

Uul

QC LU 1—

» — LU

< UJ z _ j

» •

5 o .

4/t

,

. • *.

• 1 _._.

• • • ' .

• • .

". •

-T

• •

%

.-.• ••

• ••*. I •

• 1

•. . •

' 1 ,

'. .-. •

• •

•

• . • • • *,

"

• !^ !G'"

*,

,

•

•

I

• • • * ,

• "•. ,

*. '. ' t '.-

j

: ^

' . •' ^ •

• • • • • •

' '

*

•

,* *.

•

1

1

• Wi

~

. • ••

•

1

—- • —-

o >4>

1 1

•

•

.

.•

1

1 1

wt 1 -* ! !

i

i ; • 1 • !

• 1

'.• • •

\

"

i • !

1 • " • i i • ' . . 1 1 O ; ' . • i *^

• • • " • .

t • • • . • _

• •• * .•='

,'

'•

•

/ /

4' "•^ )

exhibit any linearity of pattern and roughly corresponds

to N50°E-S50°W in Vindhyan sub-area I and N70 E-S70 W,

N50^'E-N50°W and N70°E-S70°W in Vindhyan sub-area II. The

rationale of the present study is that intersecting frac­

tures developed under primary stresses will exhibit geo­

metric relationship with the axial trends. The trend of

the intersection maxima will be either parallel or normal

to the principal elongation in a cratonic regime.

TREND SURFACE ANALYSIS OF LINEAMENT INTERSECTION DENSITY

The lineament intersection density data was subjected

to trend surface analysis by moving averages method in order

to smoothen the inhomogeneities in spatial distribution of

the data resulting from surficial cover and absence of mu­

tually intersecting lineaments in certain areas (see Ali,

1982) Two dimensional smoothening of the intersection den­

sity data was achieved by providing 88.89 % overlap. The

cell distribution grid adopted during intersection density

contour analysis (Fig. 9 ) was maintained. The Rolling Mean

Analysis was attenpted for each cell and was computed by

giving 88.89 % overlap and twice weightage to the cell

value of the central cell by using expression.

Md = ^±JL12 n

7:i

where, Md = Rolling Mean of lineament intersection density value of the central cell.

Zd = Total of the cell value of the lineament intersection density of the overlap area.

D = Cell value of the lineament intersection density of the Central cell.

n = Total number of cells

Taking these Rolling Mean values as controls, trend

surface contours were prepared by extrapolation techniques

(Fig. 11). The intersection trend surface maxima are

N50°E-S50°W, N40°W-S40°E and N36°W-S36°E Vindhyan sub-area I

and N70°E-S70°W, N20°W-S20°E and N82°E-S82°W in Vindhyan sub-

area II.

LINEAMENT INCIDENCE ANALYSIS

Following Ali (1982) and Farooqui (1984), lineament

incidence analysis was atteirpted in an effort to observe if

any meaningful correlation can be established between linea­

ment incidence and the structural fabric of the area. The

cell grid adopted for the lineament intersection density

studies was maintained. The lengths of individual linea­

ments within each cell were measured and the summation of

the lineament incidence per cell were computed and plotted

on the overlays in the central part of the cell as cell value.

The area was contoured by extrapolation technique and the

lineament incidence density contour map was prepared (Fig. 12)

<

CL

O I— z o

z

<

This map gives the major trends N54 E-S54 W in Vindhyan sub-

area I and N52°E-S52°W, N30°W-S30°E, N86°W-S86°E, m3%-S83°E

and wes'^E-SeS^W in Vindhyan sub-area II and does not show any

homogeneity of style and pattern and as such can not be of

much use for analytical purpose.

TREND SURFACE ANALYSIS OF LINEAMENT INCIDENCE DENSITY

Inhoroogeneities caused in the spatial distribution of

the lineaments due to surficial cover or the absence of linea­

ment incidence were smoothened out by giving 88.39 % overlap

to each cell value. The two dimensional smoothening of the

lineament incidence density values of the individual cells

were carried out by moving average method and Rolling Mean

values for each cell were obtained by using expression.

Md^ = < i - ^i n

where, Md. = Rolling Mean of lineament incidence density value of the central cell

Edj^ = Cell value of the lineament incidence density of the overlap area.

D^ = Cell value of the lineament incidence density of the central cell

n = Total nximber of cells

The Rolling Mean values per cell so obtained were plot­

ted in the central part of the cell, and the trend surface

contour map was prepared by extrapolation technique (Fig.13),

s:i

into

CL. <

a: =) 1/1

a z LLJ

Z

o

1^

"<•'•:

The intersection density trend surface maxima trend N52 E-S52 w

in Vindhyan sub-area I and N68°E-S68°W, N27°W-S27°E, N69°E-S69°W

and N5°W-S5°E in Vindhyan sub-area II.

Concurrence And Synthesis

The study area is located close to the Great Boundary

Fault of Rajasthan which marks the Vindhyan-Bhilwara bound­

ary in the area and show intense tectonic deformation in its

vicinity, thus the study of stress distribution becomes vital

for the proper understanding of the geological evolution of

the area. The convergence of the data generated through

photogeophysics and patterns obtained by the statistical

treatment of the structural data has led to the development

of conceptual Kinematic model for the structural evolution

of the Vindhyan Basin in Bundi area.

AXIAL TRACE GEOMETRY

The axial traces of the major folds in the area were

plotted under stereo-models and the geometry of the folded

surface was inferred from the orientation of bedding planes.

The axial traces represent the direction of maximum elonga­

tion with maximum compressive principal stress acting normal

to it, as given in table III.

Table III

Sub-Area Axial Trace Mean Axial Trace (y, Orientation orientation Trajectory

I N40°E-S40°W N44°E-S44°W N46°W-S46* i;

N50°E-S50*^W

N45°E-S45°W

N41°E-S41°W

II N70*^E-S70°W N73°E-S73°W Nl7°W-Sl7°E

N65°E-S65°W

N83°E-S83°W

LINEAMENT GEOMETRY

Trend Analysis

The lineaments observed under stereo-raodels are fract­

ure controlled. The cardinal azimuthal trends of the linea­

ments show general geometrical correlation with the axial

trace data and cr trajectories in the area. The cardinal

lineament trends of the Vindhyan sequence and their geometri­

cal relationship with 07 trajectory have been given in Table

IV.

1)

Table IV

Sub-Area Cardinal Azimuthal Trends or

of Lineaments Trajectory

I N50°E-S50°W, N40°W-S40°E N46°W-S46°£

II N70°E-S70°W, N15°W-S15°E N17*^W-S17°E

Geometric relationship of the cardinal lineament trends

with the en" trajectory suggests that genetically these frac­

tures can be classed as extensional fractures and release

fractures. The development of the extensional fractures is to

related^the tensile regime developed in the direction of

maximum elongation during folding. After the conpressive

stresses died out, the area was subjected to tensile regime

which developed in the direction of maximum conpressive

shortening. As a result, the release fractures were deve­

loped normal to the direction of maximum compressive shorten­

ing and parallel to the axial traces.

Lineament Intersection

The lineament intersection density exhibits relation­

ship with the principal elongation direction (X\ ) and maxi­

mum principal conpressive stress (cr ) . The lineament inter­

section density maxima trends obtained by extrapolatory

V i

contouring and trend surface analysis have been grouped

into two principal directions corresponding to maximurn prin­

cipal stress directions. Thoir trends have been given in

Table V.

The anomaly trends obtained from lineament intersect­

ion density maxima do not exhibit any directional correlat­

ion with 07" and X, trajectories con5)Uted independently

from the study of present state of finite strain except in

sub-area I where it exhibits some correlation with X\ tra­

jectory. Lineament intersection density maxima obtained

after Rolling Mean Analysis are in general correlation with

maximum principal stress ( CT;' ) and least stress directions

{ \ \ ) in the area. Slight variance in the trends perhaps

is due to paucity of controls in the area.

Lineament Incidence

Following Ali (1982) and Farooqi (1984), lineament

incidence density distribution was analysed to establish cor­

relation with the stress distribution system in a cratonic

regime. The orientations of the lineament incidence maxima

for the area have been given in table VI.

0)

Id H

\5-

& 0 ^ o <u

••-1 ItJ u EH

W O

• *

CO 1

3: o

yO '^ 2

M 0

rH CO 1

3: 0 r-f H 2

G (T) 0) 2

I Id

c

o

Id E •H

o 3

4) U u) Id 1-1 M-l 0) •p c

+) M c

a Id

I (d 0) c

l-H

1^

C aj X O M Id

•P M C 0) -P

Si •H (0 C « Q

(d ID

u I

^•^

o in CO I

0 o in 55

O in to I

0 o in 3

o (D ro CO I

O^ CD ro 2

O 0 O vD ^ n CO CO i I

O O O 1^ ^ m Z 2

o in CO

I M

o in

o o in CO

I

O o in 2

O

r> CO

I Cil

o u>

2

M H

Ci3 O o CN CO

I

o CM 2

o o o rvi r- CO CO CO I I

W C«J o o

O CN t - CO 2 2

2 O m VO CO

I M

O fO 2

o o <N CO

I

O o 2

s 0 o r» CO 1

M 0 o C 2

2 0 o in CO 1

J^ o o in 2

2 0 o r-CO 1

» o o r 2

H >

0)

u o

b" 0)

EH

C ft) 0) 2

I

0) C C (D -W M

O O E C - H

B O X o •P O 0) C ® +J H O

10 0) +»»« •H C M M 4) :3 o e CO

c

s

> 1 I +>

(0 -H

c c J Q

U-l 0) o o

c a <a o "0 •H -rl P O (d c -P H (d c 0) +> -H •H C X t4 0) Id

o e s

Id

u <

I

CO

u 0 (O •«» CO 1 s 0 vO "If

z

s 0 CN in CO 1 w 0 (l in 2

2 0 o\ vO CO 1 Ci] 0 a\ VO 2

on 0 r-rH CO 1 2 0 t rH Z

w o VO t-t

CO 1 2 0 VO iH

z

S 0 CM in CO 1 w 0 CM in Z

2 o 00 VO CO

u 0 (X> VO 2

2 0 a\ VO CO

bj 0 o\ VO 2

2 O

in CO

I w o in 2

H

O r- O CM in CO CO I I

r> o CM i n 2 2

r« 0 'ij'

in CO 1

» 0 ^ in 2

2 0 00 in CO 1 w o 00 in 2

ca 0 VO VO CO 1 3: 0 VO VO 2

« 2 o o CN CO in VO CO CO I I

« w o o

CM CO in VO 2 2

H

V'(

U Ci) U o o o

O VO f*> fo CO 00 CO CO CO I I I

S 2 2 o o o

O VO en CO 00 00 2 2 2

>ll

The lineament incidence density maxima exhibit random

variations caused by inhomogeneities in the outcrop distribu­

tion. However the smoothened maxima trends exhibit general

correlation with the stress distribution system. It is,

therefore, concluded that trend surface analysis of lineament

incidence densities can be helpful for stress analysis in

cratonic basins.

Structural Evolution of the Area

SOURCE AND ENVIRONMENT OF STRESSES

The study area is located on the north-western basinal

margin and shows a high degree of tectonic deformation. The

source and environment of deformation in Vindhyan Basin is

attributed to the accumulation of stress at basinal margins

(Iqbaluddin, 1979). The concept of intra-basinal stress

regime has been explained by resolution of body force into

directed stresses. The body force of the sedimentary pile and

acted against the basin floor/was resolved into vertical

and horizontal components - the former acting perpendicular

to the basin floor and controlling its bathymetry while the

latter was directed parallel to the basin floor and led to

the deformation of the sedimentary pile (Iqbaluddin et al;

1978) . The resolved horizontal conponent of the body force

of sedimentary prism acted against the basin margin and

'.n

generated a stress orthogonally to the local trends of the

basin margin.

TECTONIC STYLES AND STRUCTURAL FABRIC

The tectonic styles of the Vindhyan Supergroup are

determined by the local trends of the pre-Vindhyan fabric.

The Vindhyan basement is represented by the metasedimentary

sequence of the Bhllwara Supergroup. The regional foliation

of the Bhilwara Supergroup is represented by BS2 foliation

which is penetrative and pervasive fabric element. The orien­

tation of the foliation varies from NE-SW in the western part

to ENE-WSW in the eastern part of the area. These basic styles

are reflected in the structural fabric of the Vindhyan Supra-

crustals which have been studied in the Bundi area. The

fabric elements are expressed as NE-SW in s\ib-area I and

ENE-WSW in sub-area II. The fabric is represented by the

axial traces of the folds, the strike of sedimentaries and the

structural trends of the Great Boundary Fault and its associa­

ted thrusts which are co-directional with the pre-Vindhyan

grain of the basement rocks.

The structural evolution of the area was controlled

by deformation which was initiated pari passo with the sedi­

mentation. The accumulation of the stresses along the basin

margin led to development of folds which are cylindrical,

plane folds. With the progressive tightening, The folds

underwent changes in the geometry and tectonic styles. The

plane cylindrical geometry of the folds altered to non-plane.

non-cyclindrical style in the marginal part of the basin. This

deformation was achieved during the plastic phase of deforma­

tion. The folding took place possibly at a time when pore

water was present, which fecilitated the development of

flexural slip movement between the competent and incompetent

layers. The sedimentary pile was deformed at low strain rate

and at low pressure and tenperature levels as is evident by

the absence of planes of mechanical inhoraogeneity other than

joints and bedding. The orientation of the axial traces con­

forms with the NE-SW and ENE-WSW regional styles in sub-area

I and II.

BRITTLE FAILURE

Post tectonic to the plastic deformation, the rocks

yielded by brittle failure. The brittle phase was punctuated

by local changes in the structural styles of the fabric ele­

ments that were generated in the sedimentary prism. The tec­

tonic signatures of the brittle failure have been recorded in

the petrified geometry of the Vindhyan sedimentaries as exten-

sional (J.) and release fractures (J^)/ the Great Boundary

Fault (F-) and associated thrusts and wrench faults (F^).

Joints (J, and J2)

Two sets of joints have developed in the area. These

are vertical to sub-vertical sets and are mutually perpendi­

cular in sub-area I and li. Table VII presents the structural

Orientation of the joint sets.

Table VII

Sub-Area Orientation of Joint Sets

I N50°E-S50°W, N40°W-S40°E

II NTO'^E-STO^W, N15°W-S15°E

The joint sets roughly correspond to directions of maxi-

mxim conpressive elongation and maximum compressive shortening.

The Great Boundary Fault (F,)

The folds at the basinal margin underwent tightening and

finally gave way to peri-basinal thrusting roughly parallel to

the tectonic grain of the pre-Vindhyan metasedimentary sequence

of Bhilwara Supergroup. The tectonic plane which developed at

the interface of the Vindhyan sediments and the basement is

exhibited as the Great Boundary Fault. The Great Boundary

Fault is a curvilinear element, it is trending NE-SW in sub-

F I G . U

SYNOPTIC SCHEMATIC DIAGRAM SHOWING STRESS DISTRIBUTION AND ACCOMPANYING FINITE STRAIN IN A CRATONIC REGIME BUNDI AREA R A J A S T H A N .

I] r

area I and ENE-W5W in sub-area II. Since the deformation was

accon^lished at shallow depth, the water trapped in intergra-

nular porespaces in sediments during deposition promoted the

thrusting having a lubricating effect and reducing frictional

resistance to movement. The thrust faulting was initiated as

bedding plane thrust due to conpetence contrast and subse­

quently it was developed as decollment thrusting Vindhyan

strata on Bhilwara sequence. The Satur-Talwas and Bundi-

Indergarh thrusts follow inconpetent rock units for most of

the part and presumably came into being as a result of imbri­

cate thrust faulting at a later stage in response to stratal

shortening. The development of these thrusts postdates the

folding as the structural trends are terminated against the

Great Boundary Fault.

Wrenches (F2)

Secondary faulting was acconplished at a later stage

in the structural evolution of the area. Two sets of wrench

faults have been recognised- NNW-SSE trending left lateral

faults and WNW-ESE trending right lateral wrench. The Vindhyan

sedimentation yielded to failure at low angles to lines of no

finite longitudinal strain. The shears were developed due to

positive elongation along the strand and negative elongation

normal to the strand. The wrench faults developed essentially

with a strike slip component. The dip slip was initially

low. Due to progressive deformation in the area around Satur,

a rotational shear developed along the right lateral Bundi-

Satur wrench which resulted in the development of Barodia

horst.

M7

Chapter VI

SUMMARY AND CONCLUSIONS

The present study was directed -cc investigate the geo-

logy^geomorphology and structure in parts of Bundi district,

Rajasthan and to assess the potentiality of the remotely

sensed data for these studies. The study was carried out by

detailed interpretation of aerial photographs and 'UandS.sat ima­

gery. Field checks at key areas were undertaken to establish

the correlation between photo-interpretation and existing re­

alities in the field. The study was extended to an area of

about 2,800 sq. kms. falling between north latitude 25^18'4 7"

and 25°43'34" and east longitudes 75°21'36" and 76°5«0". Data

generation of the geological,structural and geomorphological

elements in the area was carried out through concurrence and

synthesis of spectral and geotechnical characters in collation

with secondary data.

A model for landscape evolution in parts of Vindhyan

Basin in Rajasthan was worked out by study of spectral and

geotechnical expressions of constructional and erosional

landforms under stereo-models. The geomorphic evolution has

been polycyclic. The first cycle was erosional which gave rise

II. r^

to Vindhyan surface roughly corresponding to 475 m elevation.

The second cycle generated landscape inhonnogeneities manifes­

ted as structural hills and structural valleys of Vindyans,

structurual hills, pediment, shallow buried pediment and buried

pediment in Bhilwara terrain. It was controlled by sheet wash

and led to the development of Bhilwara surface corresponding to

an elevation of 260 m. The third cycle was marked by deposition

of Chambal alluvium and led to the development of Chambal sur­

face roughly corresponding to an elevation of 228 m. This

cycle ccirved out a zone of talus and scree fans west of Bundi

and extensive structureless alluvial plains.

Interpretation keys of the various lithostratigraphic

units have been developed based on variable tonal densities,

erosional resistance, drainage and channel pattern together

with landuse pattern, vegetation and structural expression.

The stratigraphy of the Bhilwara and Vindhyan Supergroup in

the area has been studied with the help of photo-characters

together with selective ground truth. The following order

of superposition has been observed:

Vindhyan Supergroup

' hander group

Rewa Group

Kaimur Group

Sirbu Shale Lower Bhander Sandstone Samaria Shale Bhandar Linestone Ganurgarh Shale

Upper Rewa Sandstone Jhiri Shale Lower Rewa Sandstone Panna Shale

Kaimur Sandstone

Bhilwara Supergroxip

Great Boundary Fault

Quartz Reefs Hindoli Group Quartzite

Pelitic Metasedaments

Base Not seen

(H i;j

The present study has established that the photo recog­

nition characters based on reflectance and landform character­

istics can serve as guides for rapid lithological and geomor-

phological mapping.

Structural geology of the area was worked out through

study of strain generated photo-fabric. Structural data was

generated through photogeophysical interpretations. Based on

structural peculiarities and stratigraphy, the area was divi­

ded into Bhilwara and Vindhyan tectonic systems separated by

the Great Boundary Fault, The Bhilwara sequence has been

subjected to at least two generations of folding and has

undergone low grade regional metamorphism. The Vindhyan

sequence show peri-basinal deformation and a number of folds

and dislocations have been mapped.

Photo-geophysical studies involving azimuthal distri­

bution, lineament intersection density and incidence density

were taken up in an integrated approach to decipher the tecto­

nics and structural evolution of the area. The fold geometry was

evaluated through variance of strike and dip of the plane of

stratification. The maxima obtained from statistical treat­

ment of joint controlled lineaments were interpreted in rela­

tion to CrY trajectories.

Lineament data was statistically treated through circu­

lar ray diagrams with the class interval of 10 in respect

of percentile frequency and percentile length. The lineament

azirauthal maxima were subjected to mathematical mean analysis

to obtain cardinal lineament trends. The cardinal lineament

orientation data were utilised in conceptualisation of kine­

matic model for the stress distribution in the area.

The lineament intersection density data were used for

conputation of OT trajectories independently of the trend

analysis. The area was divided into a convenient grid of

cells of 25 sq. kms. area. The number of lineament intersec­

tions in each cell was plotted as the central cell value. The

area was contoured by extrapolation method, taking central

cell values as controls. The contour maxima were obtained

and correlation between the maxima and the ot trajectories

for the sub-areas was attempted. Two dimensional smoothening

of the intersection density data was achieved by Rolling Mean

Analysis. The data was smoothened out by providing 88.89 %

overlap and twice the weightage to the central cell. These

cell values were used for preparation of trend surface contours

The lineament intersection trend surface maxima were plotted

and correlated with the stress regiire.

The lineament incidence density analysis was attempted

to find out if any meaningful correlation can be established

between the lineament incidence and the structural fabric of

the area. The cell grid adopted during lineament intersection

density analysis was retained and the summation of the length

of individual lineaments were plotted as cell values. The

area was contoured by extrapolation techniques using the

lineament incidence values as control to obtain lineament

incidence density map. The inhomogeneity caused in the spa­

tial distribution of lineaments due to surficial cover or

absence of lineament incidence were smoothened out through

trend surface analysis. The values obtained after Rolling

Mean Analysis were used to prepare lineament incidence trend

surface map and trends of maxima of lineament incidence were

obtained.

The concurrence and synthesis of the azimuthal orien-and

tation of lineaments intersection/incidence density suggest

good correlation with o trajectories of the various sub-

areas .

The deformation of Vindhyan Basin took place under a

centrifugal stress field. The source and environment was

intra-basinal. The lithostatic stresses contributed to peri-

basinal deformation through accumulation of stress along a

rigid margin. The cr( trajectories were controlled by the

pre-Vindhyan grain of the Bhilwara Supergroup. The deformation

11).:

was initiated under plastic regime. It continued through

brittle-ductile transitional failure to brittle regime. The

dominant structural trends are codirectional with the basement

structure. The deformation took place pari-passo with sedi­

mentation and the Great Boundary Fault of Rajasthan possibly

represent a bedding thrust which transgressed onto the eroded

basement as erosion bedding thrust.

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