Lineament Fabric of Rajasthan and Gurajat, India

LINEAMENT FABRIC OF RAJASTHAN AND GURAJAT, INDIA

P.C. Bakliwal and SM. Ramasamy,

Abstract

A study of Landsat imagery covering the states of Rajasthan and Gujarat, on scales of 1:1 million and 1:0.5 million, using black and white paper prints and transparencies, reveals a panorama of lineaments, traversing and criss-crossing different strata of varying lithology and age. These lineaments have variable extent, different azimuthal orientation and fluctuating density distribution. Based on their extent, the lineaments have been classified as major (>300 km), intermediate (300 - 100 km) and minor (<100 km).

The major lineaments generally represent the surface signatures of crustal fractures of deep seated nature and seem to have played a significant role in the tectonic evolution of different sedimentary basins of Archaeozoic to Cenozoic. These lineaments have interbasinal extent. The intermediate lineaments are more frequent in number and generally related to the tectonic history of the individual sedimentary basins, representing faults, axial trace of regional folds and group / formational boundaries. These are mostly intra-basinal lineaments. The minor lineaments are maximum in number with varying distribution and are expressions of faults, fractures, dykes and axial traces of large scale folds.

The direct relevance of these lineaments with magmatism, mineralisation and tectonism have been identified.

INTRODUCTION

Linear features on the surface of the earth have long been recognised through geologic, geomorphologic and geophysical data. Their linearity, extent and distribution, could be appreciated only after the availability of satellite and airborne data. Such significant linear and curvilinear features on the earth’s surface were named as ‘lineaments’ by Hobbs (1904). The literature in the later part of the 20th century has helped significantly in understanding the morphology and genesis of the lineaments. Geoscientists by and large accept the view that the lineaments are surface expressions of faults, fractures, continental margins and submarine ridges (Sonder 1947; Wilson, 1948; Kaisar, 1950; Hills, 1963; Billings, 1972; Kelley, 1955; Sharma et al., 1982 and Bakliwal et al., 1983).

The satellite MSS data of Rajasthan and Gujarat were studied on all four bands (namely 4,5,6 and 7) on paper prints and transparencies of 1:1 million and 1:0.5 million scales, to infer the linear features, based on tonal and textural contrasts. Such lineaments were further screened for any man made linear features. The man made linear features were filtered out and lineaments related to geological processes were drawn and a lineament map was prepared on 1:106 scale. The analyses of these lineaments show their close relationship with evolution of the different sedimentary basins of varying ages from Proterozoic to Cenozoic, magmatism,

Reprinted from Rec. Geol. Surv. India (Jaipur) 113(7) : 54-64 - 1987 mineralisation and groundwater. The paper describes the dispositions, geological and tectonic significance of the important lineaments.

REGIONAL GEOLOGY

The states of Rajasthan and Gujarat form the western most part of the Bundelkhand craton. This region was an active zone of sedimentation, distinct tectonism and repetitive magmatism. The Banded Gneissic Complex acted as the basement during the Precambrian times for the Proterozoic basins like Aravalli, Delhi (Heron, 1936) and Vindhyan (Coulson, 1928). While the basement rocks comprise a complex assemblage of high grade metamorphites, the Aravalli basin is composed of a thick pile of low-grade metamorphites and complexly folded clastic sediments with minor chemogenic assemblage. The Delhi contains distinctly well defined calcareous, arenaceous and argillaceous assemblages. The characteristic repetitive deformative episodes and magmatism typically signify geosynclinal nature of sedimentation and deformation of these basins, whereas the Vindhyans provide a characteristic example of intracratonic sedimentation with independent style of deformation. The sedimentation, deformation and tectonic evolution of these Proterozoic basins were studied in detail by Heron op. cit., Coulson op. cit., Datta and Ravindra (1980) Gupta et al. (1981) and many others in selected areas.

The Vindhyan sedimentation in the end phase was succeeded by the sedimentation of Marwar Supergroup of rocks in the trans-Aravalli region. The western Rajasthan and the northern Gujarat witnessed restricted sedimentation of clastic sediments during the Mesozoic while the Cenozoic sea was widespread in western Rajasthan. Repetitive acidic, basic and ultrabasic magmatism during the Proterozoic, widespread acidic volcanism at the end of Proterozoic and an extrusion of basaltic flows during the end of Mesozoic are significant magmatic events of the region.

LINEAMENTS

The lineaments of Rajasthan and Gujarat show a spectacular network traversing the rock types of varied ages (Fig.1). These lineaments vary from 2 km to more than even 1000 km in length with linear and curvilinear expressions. The study of these lineaments in relation to geology, structure, magmatism, mineralisation and deep geophysical responses etc. led to the classification of these lineaments into various groups and classes.

Based on the length of individual lineaments, such lineaments in other parts of the world have been classified by Heman (1961) as mesofractures (> 2 miles) and microfractures (<2 miles) and by Blanchet (1957) as microfractures (less than 2 miles) and macrofractures (2 to 50 miles). The lineaments of Rajasthan and Gujarat have been broadly classified as major (more than 300 km in length), intermediate (300 – 100 km) and minor (less than 100 km) – Ray et al. 1980, Sharma et al. 1982, Bakliwal and Ramasamy, 1983a, 1983b. Bakliwal et al. (1983) have classified these lineaments on the basis of their geological significance into inter basinal and intra basinal lineaments, the former traversing a number of basins of varying ages and the latter confined to a single sedimentary basin. The authors in the present communication have

55 further analysed these lineaments and brought out their detailed morphology and their geological significance.

The well exhibited lay-out of major lineaments of the area under study broadly fall under three azimuthal distributions with NNW-SSE, ENE-WSW and NW-SE orientations. The intermediate lineaments fall almost under the above three lineament systems showing sub parallelism to the nearby major lineaments. The minor lineaments, however, are randomly oriented in the area with rare preferred orientations.

The major lineaments are very broadly and unequidistantly spaced, whereas the intermediate lineaments exhibit with moderate density with more frequency in Aravalli, Delhi and Vindhyan basins. However, the density of major, intermediate and minor lineaments is poor in the western desert tract of Rajasthan.

MAJOR LINEAMENTS

The present area is traversed by a number of major lineaments running for more than 300 km to even upto 1000 km across Archaean to Cenozoic rocks and hence the majority of them are interbasinal lineaments. These major lineaments are predominantly aligned in NNE-SSW, NW-SE and ENE – WSW directions, systematically disposed / placed and regionally control the geology of the area. The detailed study shows that these lineaments played significant role in the tectonic evolution of the different sedimentary basins from Proterozoic to recent times (Bakliwal et al. 1983). A brief description of the major lineaments is given as follows.

NNW – SSE and NNE – SSW Trending Lineaments :

Udaipur – Sardarpur lineament (No.I)

The Udaipur – Sardarpur lineament trends in a NW – SE direction between Udaipur (24º34’ : 73º42’) in the northwest and Sardarpur (22º38’ : 75º00’) in the southeast for a distance of about 300 km. In its southern part it is expressed as a linear escarpment in Deccan Trap and controls the Mahi river course in its central part. It forms the contact between the Debari and Udaipur Group of rocks (Aravallis) and in the northern part it is a well defined boundary fault between the Aravalli basin and the pre-Aravalli basement rocks (Bhilwara Super Group). The occurrence of tight isoclinal folds with NW – SE trend in the Debari Group (Aravallis) of rocks in the east and tight upright synclines and anticlines with the same trend in the Udaipur Group (Aravallis) of rocks in the west of this lineament, most probably, indicate that this lineament has acted as a barrier during deformation. It would have also been the source of synsedimentational basic volcanic rocks during the inception of the Aravalli basin. The occurrence of Gingla Granite (2960 m.y.) along this lineament may probably indicate their inter-relationship. This lineament forms the eastern boundary / fault of the Aravalli basin. The occurrence of base metal mineralisation in Phalet (24º 31’: 73º55’) and Kotri (24º 45’ : 73º 47) area at the contact of pre-Aravalli basement and the Aravallis along this lineament zone indicates that this lineament warrants detailed studies throughout its strike length for incidence of base metal mineralisation.

Rakhabdev Lineament (No.II)

Rakhabdev lineament, named after the Jain pilgrim centre, is a curvilinear lineament whose curvature conforms to the western margin of the Bundelkhand massif and it extends from Nathdwara (24º55’ : 73º50’) in the north to Barwani (22º00’ :74º 56’) in the south for a distance of about 350 km. This lineament which was known for a distance of about 140 km. between Nathdwara in the north and Lunawada (23º06’ : 73º40’) in the south (Sharma et al., 1982) has now been extended up to Barwani situated on the southern bank of Narmada river (Anon, 1983). Its southern extension beyond the Narmada river for another 50 to 100 km could also be traced locally. It distinctly exhibits dark tone between Nathdwara and Dungarpur (23º49’ : 73º44’) and defines a linear escarpment in the Deccan Trap in its southern part, south of Banswara (23º33’ : 74º26’). This lineament is aligned almost in the axial portion of the Aravalli basin, and both the eastern and the western margins of the basin are parallel to this lineament. This lineament traverses the older and the younger sequences of the Aravalli Supergroup and also the Deccan Trap, indicating its reactivation during the Proterozoic and Cenozoic and acted as zone of maximum sinking during the Aravalli sedimentation. The occurrence of large scale folds with NE-SW trending axial traces in the west and E – W trending axial traces in the east of this lineament in Lunavada Group of rocks (Aravallis) in the area between Dungarpur and Sallopet shows its influence in the Aravalli deformation. Besides, its deep crustal nature is also well marked by the occurrence of ultrabasic suite of rocks all along this lineament between Nathdwara and Lunavada and a carbonatite body at Barwani.

In the light of the above, the extension of this lineament between Lunavada and Barwani becomes significant for the search of ultrabasics and related mineral occurrences.

Kishangarh – Chhipri Lineament (No.III)

The NNE – SSW trending 450 km long major lineament is a very significant one in the geological and structural history of the Aravalli range of Rajasthan. Between Keilwara (25º10’ : 73º44’) and Kishangarh (26º22’ : 74º54’) it defines the contact between two contrasting geomorphic regimes – the linear structural hills of the Aravalli range in the west and the pediplained pre-Aravallis in the east. It also forms the fault contact (Heron, 1936) between the Delhi metasediments in the west and the pre-Aravalli basement in the east indicating that it acted as the eastern basin margin fault of the Delhi sequence between Keilwara and Kishangarh. The lineament segment between Keilwara and Himmatnagar (23º50’ : 73º00’) , demarcates the Delhi basin against the Aravallis and further extends up to Chhipri (22º55’ : 72º55’), east of Ahmedabad, through the thick alluvial country exhibiting a darker tone. Its deep seated nature is well indicated by the occurrence of ultrabasic suite of rocks to the west of Udaipur and alkaline rocks near Kishangarh.

57 Pisangan – Vadnagar lineament (No. IV)

The NNE – SSW trending Pisangan – Vadnagar lineament which runs for more than 320 km between Pisangan (26º40’ : 74º25’) in the north and Vadnagar (23º47’ : 72º41’) in the south played a crucial role during Delhi orogeney. It limits the western margin of the Aravalli range. In the north between Pisangan and Phulad (25º 37 : 73º 50’) it is a fault within the Ajabgarh metasediments of Delhis whereas in the central part in between Phaulad and Sadri (25º 10’ : 73º 28’) it marks the contact between the linear structural hills of Delhi rocks and the pediplained post-Delhi Erinpura granite. The lineament from Sadri to Vadnagar once again traverses within the Ajabgarh Group of rocks and defines the eastern boundary of the Sendra – Ambaji synorogenic granite. While the eastern boundary of the Delhi basin is controlled by the Kishangarh – Chhipri lineament, its western margin in the Aravalli range is partly controlled by this lineament. Evidently, it is a deep seated fault / lineament, which probably controlled the emplacement of the ophiolite suite of rocks between Pisangan and Sadri (Phulad ophiolite, Gupta et al., 1981). Between Sadri and Vadnagar it would have also acted as a conduit for the Sendra – Ambaji synorogenic granite.

Gravity data of the area further indicates that the Pisangan – Vadnagar lineament marks the contact between the Degana low gravity zone in the northwest (Reddy and Ramakrishna., 1981) and the high gravity zone in the southeast occupied by Delhi metasediments in the southeast. The uplifting of the NNE- SSW trending Delhi blocks of the Aravalli range has taken place along the two deep seated lineaments.

Sadri – Palanpur lineament (No.V)

The western fringe of the Aravalli hill range in the southwest extremity is marked by another major lineament with NE – SW trend running between Sadri in the noth and Palanpur (24º10’ : 72º27’) in the south. This lineament limits the main Aravalli hill range in the east and the pediplained Erinpura granite in the West. Gupta et al. (1981) postulated a lineament extending from Pisangan to Palanpur and named it as Phulad lineament, whereas this study clearly shows two lineaments, namely Pisangan – Vadnagar and Sadri – Palanpur lineaments having their junction at Sadri. The triangular area bounded by these two lineaments is profusely intruded by Sendra – Ambaji synorogenic granite (800 – 1850 m.y.) and ophilolite suite of rocks.

Sirohi – Disa lineament (No.VI)

Although this lineament has a limited extent, it is grouped with major lineaments owing to its geological significance. It occupies the central portion of Sirohi Group of rocks (Gupta et al. 1981) Delhi Supergroup, and probably this was responsible for the formation of the isolated younger Delhi trench / basin in Sirohi area. The occurrence of metavolcanics (Punagarh and Sindreth Group) along and in the vicinity of this lineament leads to the inference that it also may have been the passage for Punagarh and Sindreth volcanism.

58 Luni – Sukri lineament (No.VII)

The NE-SW trending 750 km long lineament aligned along Luni and Sukri rivers forms a significant linear / curvilinear feature in the desert tract of Rajasthan. It extends from the Great Rann of Kutch in the southwest to Sambhar Lake (27º 00’ : 75º00’) in the northeast with a ENE – WSW to NE-SW trend. In the southwest in Kutch it marks the contact between the Great Rann of Kutch and the dune fields, thereby defining or rather controlling the northern growth of the Great Rann of Kutch. The northeastern extension of the Luni-Sukri lineament between Bakhasar (26º 46’ : 71º 10’) and Sambhar Lake is controlling the Luni and Sukri rivers in the desert country. The absence of Delhi outcrops northwest of this lineament in the desert areas indicates that this lineament might represent the northwestern limit of the Delhi basin. The gradual youngling of the Delhi metasediments towards northwest and the occurrence of lineaments from III to VII indicate that these lineaments have reactivated in the order III to VII, though these are contemporaneous. The latest amongst these lineaments to reactive is the Luni – Sukri lineament which culminated the Delhi orogeny and also emplaced the Malani suite of rocks (505 - 735 m.y.) (Bakliwal and Ramasamy, 1983a). The absence of Cambrain sediments belonging to Marwar Supergroup beyond southeast of this lineament significantly show that this lineament would have limited the Cambrain basin in the southeast during the evolution of the Cambrain basin. The alignment of earthquake epicenters of varying dates from 1819 to 1976 A.D. in Kutch area, indicates neotectonism along this lineament.

It is significant to note that the intersection of Luni – Sukri lineament with NW – SE trending Jaisalmer - Barwani Lineament (No.IX) located near Jhab (25º00’ : 71º52’) is marked by a prominent gravity low of –30 mgal (Reddy and Ramakrishna, 1981) whereas gravity high was recorded along this lineament north of Pali (25º46’ : 73º21’) . A subparallel lineament (VII A) located between Mukalsar (25º35’ : 72º34’) and Degana (26º53’ : 74º21’) seems to be a part of the Luni – Sukri lineament system. It further extends in northeast from Sikar (27º35’ : 75º11’) to beyond Delhi and runs through Indo-Gangetic alluvium and finally joins the Ganga tear in Siwaliks southeast of Dehradun.

NW – SE trending lineaments

In the lineament fabric of Rajasthan and Gujarat, the NW – SE trending spectrum of lineaments also form a significant lineament system. The major lineaments having this azimuth group are the west coast lineament (No.VIII), Jaisalmer – Barwani lineament (No.IX), Ajmer – Sandia lineament (No.X), and Raisinghanagar – Tonk lineament (No.XI)

West coast lineament (No.VIII)

The NW – SE trending 600 km long lineament traversing between Bulsar (20º36’ : 72º56’) in the southeast to Kalner (25º20’ : 70º45’) in the northwest is a significant lineament. Though it is not exactly parallel to the west coast of Indian Peninsula, it is aligned in the northwestern extension of the west coast. It acts as a clear line of divide between Saurashtra Peninsula and the Ahmedabad piedmont zone and further northwest, it limits the northeasterly growth of Little and Main Rann of Kutch. It is a tectonically active deep seated dextral fault

59 along which the western extension of Narmada lineament has been shifted. It might probably be the surface manifestation of Cambay graben.

Jaisalmer – Barwani lineament (No.IX)

It is a 1000 km long lineament extending from Barwani (22º00’ : 74º56’) in the southeast to Jaisalmer (26º54’ : 70º56’) in the northwest in a NNW – SSE to NW – SE direction, the major segment of which passes through the desert tract (Anon., 1983). It delimits the southwestern boundary of the Aravalli basin near Godhra (22º46’ : 73º38’) and abruptly cuts the Delhi rocks in their southwestern extension in Vadnagar and Palanpur areas. North of Barmer, it delimits the western boundary of the Tertiary basin, and crops out as a well defined fault within the Mesozoics of Jaisalmer area. Its further northwestern extension could be traced upto Afghanistan through Pakistan as the Mari – Jaisalmer Arch (Dasgupta, 1975; Anon., 1983). A few circular features located along this lineament in Jaisalmer area are interpreted as sub surface domes and basins associated with tectonism of this lineament, which may be the promising zones for hydrocarbon accumulation (Bakliwal and Ramasamy, 1983b). Near, Godhra, it is also a fault between the Godhra granite (1955 m.y.) and the metasediments of Lunavada Group. The intense deformation of the Lunavada Group of rocks in the area bounded by this lineament and the Rakhabdev lineament may be the result of simultaneous reactivation of both the lineaments. This lineament traverses the rocks of different ages varying from Precambrian to Tertiary. This feature indicates its reactivation over the periods. Granites near Godhra, Malani volcanics near Barmer, falling on this lineament, further confirm its deep seated nature. Carbonatite body at Barwani is located at the junction of Rakhabdev and this lineament. Significant difference in the gravity anomaly is noted on either side of this lineament in Godhra – Barmer section with gravity high (10 to 30 mgal) values in southwest and low (-10 to – 30 mgal) in northeast.

Ajmer – Sandia lineament (No.X)

Ajmer – Sandia lineament trends in a NW – SE direction and runs over a distance of 550 km between Sandia (22º45’ : 76º20’), Madhya Pradesh in the southeast and Ajmer (26º26’ : 74º40’) in the northwest. It runs from the monotonous Deccan Trap in the southeast, cuts across the Vindhyan plateau, traverses the pre-Aravalli pediplain and finally cuts the Delhi hill ranges perpendicular to the regional trend. It is a well defined fault in the Vindhyans of central India between Sandia and Bhopal, forming major fractures in Deccan Trap between Bhopal and Jhalawar (24º35’ : 76º11’) and coinciding with the contact of the Lower Bhander Sandstone and the Sirbu Shale of Vindhyan sediments between Jhalawar and Bundi (25º26’ : 75º38’) However, its expression is a simple linear feature in the pre-Aravalli granitic and gneissic country between Bundi and Ajmer. In Ajmer where it cuts the Delhi’s contrasting lithologies occur on either side of this lineament. The consistent calcareous and argillaceous facies of rocks which run continuously between Khedbrahma (24º00’ : 73º00’) in the south and Ajmer in the north changes into a monotonous arenaceous facies in the northeast beyond this lineament near Ajmer. This shows that this lineament could have acted as a barrier within the Delhi basin during sedimentation. In pre-Aravallli country it forms a potential zone for groundwater (Ramasamy and Bakliwal, 1983b).

Raisinghnagar – Tonk lineament (No.XI)

Although this lineament runs over 400 km in NW – SE direction between Raisinghnagar (2930: 73º26’) and Tonk (26º09’ : 75º48’) , its geologic and tectonic significance is not known due to its being mostly in desert country. It demarcates the contact between the dune invaded pre-Aravalli pediplain of Jaipur region and the dune-free Bhilwara region. However, the availability of additional subsurface data may bring out its tectonic significance. The possibility of high discharge aquifers along this lineament in the desert tract cannot be ruled out (Ramasamy and Bakliwal, 1983a).

ENE – WSW trending lineaments :

The ENE – WSW trending set of lineaments also form a prominent lineament pattern. These are Son – Narmada lineament (No.XII), Chambal – Jamnagar lineament (No.XIII), Chittaurgarh – Machilpur lineament (No.XIV) and Bharatpur – Mount Abu lineament (No.XV).

Son – Narmada lineament (No.XII)

The ENE – WSW trending Son – Narmada lineament is a notable lineament occurring at the contact of southern peninsular shield and the northern extra-peninsular landmass. This distinct lineament of the Indian sub-continent runs for a distance of more than 1000 km and is aligned along the Son river in the eastern sector and the Narmada river in the central sector. Its eastern extension up to Assam Plateau and the western continuity up to Madagascar, cutting across the Saurashtra peninsula (Crawford, 1978) could be traced. The rectilinearity of the Narmada, Son and Tapti valleys, their striking parallelism and the associated geomorphic features were well appreciated on topographic sheets even by the earlier workers (Oldham et al. 1901, Vredenberg, 1906). Since then many concepts and postulations were generated to explain the linearity and extent of Narmada - Son – Tapti valleys as rift valleys, graben structure, plate margin, deep crustal fracture, mantle plume etc. (Choubey, 1979; Ghosh, 1976; West, 1962).

The present interpretation of Landsat imagery of the western sector of Narmada lineament falling in Gujarat region adds significant details on the nature of the western extension of the Narmada lineament in the form of 130 km wide graben (Anon., 1981). While the central sector of the Narmada lineament represents the southern boundary of the Vindhyan basin of central India, its western extension in Surat area traverses the Deccan Trap country. Further west it continues in Saurashtra peninsula with a northwesterly shift of 20 to 30 km along Cambay graben / west coast lineament (No.VIII). Its expression in Saurashtra peninsula is in the form of four well defined ENE – WSW trending sub-parallel lineaments (Ramasamy, 1985) among which the northern most lineament traversing Bhavnagar (21º46’ : 72º10’), Babra (50’ : 71º18’) and Bardha (21º50’ : 69º45’) is the actual western continuity of the Narmada lineament. The other sub – parallel lineaments No. XII A, XII B and XII C are also significant deep seated lineaments among which lineaments XII A traverses Amreli (21º35’ : 71º13’) and Junagarh

61 (21º31’ : 70º29’), No.XIIB passes near Sawar Kundla (21º20’ : 71º19’) and XII C defines the Saurashtra coast and runs within the mainland upto Dabhoi (22º07’ : 73º27’) area. These lineaments (XII, XIIA, XIIB and XIIC ) act as boundaries between various geomorphic provinces like mesa, butte, buried pediment and cuesta complexes in Deccan volcanics. The deep seated nature of the Narmada lineament is unquestionable as indicated by magmatism – the carbonatite plug at Barwani and Ambadongar in the east mainland and Bhavnagar and Bardha igneous suite of rocks in Saurashtra peninsula. The Junagarh magmatic suite along lineament No.XIIA, a carbonatitle dyke (?) along lineament No.XIIB and a hot water spring along lineament XIIC favour their deep seated nature.

Chambal - Jamnagar lineament (No.XIII)

While the Son – Narmada lineament marks the southern boundary of the Vindhyan basin of central India, the northwestern margin of the Vindhyan basin is controlled by a system of lineaments and faults. The Chambal – Jamnagar lineament is one such lineament occurring near the northwestern boundary of the Vindhyan basin and extending over a distance of more than 900 km from Dholpur (26º40’ : 77º54’) in the northeast to Jamnagar (22º28’ : 70º04’) / Little Rann of Kutch (Gulf of Kutch) in the southwest. Between Dholpur and Pali (25º50’ : 76º36’) , it controls the course of the Chambal river from west Pali to Chittaurgarh (24º52’ : 74º40’) it traverses the Vindhyan sediments and further southwest it cuts across the pre-Aravalli pediplain, cuts and Aravallis south of Udaipur, passes through west of the Banas river and ultimately terminated in the Gulf of Kutch traversing the alluvial tract. Between Dholpur and Pali it runs within the flat lying Vindhyan sediments and limits the southern margin of the upper Bhander sandstone plateau, indicating its possible control in sedimentation of the upper Bhander sandstone. Between Sawai Madhopur (26º00’ : 76º24’) and Bundi (25º26’ : 75º39’) it is a contact between the platformal Vindhyan sediments in the SE and the intensely deformed Vindhyan in the NW. It is expressed as a fault in Parsoli (25º07’ : 74º55’) - Pichhor area. The opened up sub-parallel set of fractures in the Aravallis represents this lineament. The well defined ENE – WSW trend of the Gulf of Kutch indicates that its growth may be related to the lineament. The occurrence of Berach Granite (2585 m.y.) and Untala Granite (2960 m.y.) along this lineament in the pre-Aravalli country may indicate its significance in the magmatic episode along this lineament. Passing of this lineament along rocks of pre-Aravalli to recent times is indicative of its intermittent reactivation.

Chittaurgarh - Machilpur lineament / Great Boundary Fault (No.XIV)

The Chittaurgarh – Machilpur lineament which runs for a distance of over 400 km. With a ENE – WSW trend, forms a part of the Chambal – Jamnagar lineament system. It divides the area into two distinct geomorphic units viz. Bundi – Sawai Madhopur hill ranges in the south and the pediplained pre-Aravalli rocks in the north. It is a well defined fault, namely the Great Boundary Fault (Coulson, 1927) marking the northwestern boundary of the Vindhyan Basin. It is a pre-Vindhyan grain which got reactivated during the sedimentation and deformation of the Vindhyan sediments. (Iqbaluddin et al. 1978). Morphologically it is a normal gravity fault occurring at the margin of the basin along which gradual sinking of the basin floor took place. The present reverse geometry of this fault with thrusting at places in which the pre-Aravalli basement rocks are brought in juxtaposition with the Vindhyan sediments indicates reactivation

62 of this lineament simultaneously with sedimentation and deformation of the Vindhyan sediments. Neotectonic features have also been observed along the lineament (Bakliwal and Sharma, 1980). The southeasterly and the northeasterly migration of the Chambal and Jamuna rivers respectively indicates the uplift of Vindhyan rocks which could have taken place only along the Chambal – Jamnagar and Chittarugarh – Machilpur lineaments. Within these two lineaments, there are a number of sub-parallel faults / lineaments forming a part of this lineament system. This lineament which all along acts as basin margin fault between Sawai Madhopur and Chittaurgarh continues further northeast between Sawai Madhopur and Machilpur as an intrabasinal fault within the Vindhyan sediments. Its further extension in the northeast beyond Agra beneath Jamuna alluvium is seen.

A sub-parallel lineament (No.XIVA) located to the northwest of this lineament between northeast of Sawai Madhopur and west of Agra is yet another lineament belonging to this system and forming a part of the Great Boundary Fault. It is 180 km long and represents the northwestern boundary of the Vindhyan basin.

Bharatpur – Mount Abu lineament (No.XV)

The Bharatpur – Mount Abu lineament running between Bharatpur (27º15 : 77º23’) in the northeast and Mount Abu (24º36’ : 72º48’) in the southwest is a significant deep seated lineament, traversing the pre-Aravalli country of central Rajasthan. Todabhim - Kakor and Banas lineaments traced earlier (Sharma et al.1982) forms segments of this lineament which extends over a length of 550 km. In Bharatpur – Pipalda (26º24’ : 76º22’) section it is a deep seated fault and from Pipalda to Bhilwara, it distinctly demarcates the low grade metamorphites belonging to Hindoli Group (pre-Aravallis) and the high grade migmatitic rocks of Sandmata Complex. Further, north of Udaipur, it changed the configuration of the eastern margin of the Aravalli basin. This lineament in this sector acted as an active sedimentational and deformational barrier as seen from contrasting lithology and fold style on north and south of this lineament in Nathdwara area. The incidence of Berach and Mount Abu Granites along this lineament may probably indicate their interrelationship with this lineament. It is significant to note hot springs in the proximity of this lineament in Todabhim (26º55’ : 76º50’) area. The lineament segment forming the contact of the pre-Aravalli basement and the Aravalli basin southeast of Nathdwara may form favourable loci for base metal mineralisation and needs further studies in the light of the base metal occurrences in Phalet – Kotri belt. This lineament is a significant groundwater tapping zone in pre-Aravalli granitic and gneissic country as evident from the alignment of high discharge wells along this lineament (Ramasamy and Bakliwal, 1983a).

N – S trending lineaments

Though western India is predominantly traversed by a spectrum of NNE – SSW, NW – SE and ENE – WSW trending lineaments, the lineaments with N – S azimuthal orientation are seldom found.

Lathi – Rajkot lineament (No.XVI)

63 This N – S trending lineament traverses between Lathi (27º00’ : 71º32’) in the north to west of Rajkot (22º18’ : 70º48’) in the south. It gives a markable tonal contrast in Landsat imagery cutting across the desert tract. It originates from Deccan trap country in the south near Rajkot, cuts across the Jurassics in Kutch area, traverses the Thar desert by forming a minor escarpment in the dune field between Bhuj and Barmer (25º42’ : 73º25’) and cuts across the Mesozoics in Jaisalmer area. Its occurrence in Mesozoics and in the Cenozoic sediments indicates that it would be a pre-Mesozoic lineament which later got reactivated in Tertiary times. This lineament most probably represents a fault in the Jurassic rocks. As this lineament cuts across a number of NE – SW trending major and intermediate lineaments in Kutch, desert tracts of Barmer and Mesozoic of Jaisalmer, their intersection points may act as potential groundwater resources (Ramasamy and Bakliwal, 1983a).

INTERMEDIATE LINEAMENTS

While the major lineaments are inferred as deep crustal fractures favouring magmatic episodes and are acting as boundaries of basins and faults at basin margins showing significant involvement in the tectonic evolution of Proterozoic, Mesozoic and Cenozoic basins, the intermediate lineaments (100 – 300 km long) are confined normally within a single basin or rocks of same age (Bakliwal et al, 1983). The relation of these lineaments to geology and structure of the area shows that these are mainly the surface expressions of lithological contacts, axial plane fractures of folds, faults and the master fractures. Some of the significant intermediate lineaments (1 to 28) are as follows.

A set of NE – SW trending parallel lineaments (No.1, 2 and 3 in Fig. 1) found in Chittaurgarh area are tectonic features associated with the Great Boundary Fault. The lineament No.1 seems to be the extension of the Great Boundary Fault, and 2 and 3 are sympathetic fractures. The intermediate lineaments (No.4 and 5) found between Udaipur and Rakhabdev with ENE – WSW trend are sympathetic fractures to the Chambal – Jamnagar lienament (No.XIII). These lineaments (4 and 5) exhibit clear open fractures in Aravalli metasediments. The lineament No.4 may be significant in search of base metal occurrences as it lies in close proximity of the Sawar lead-zinc deposit.

The NE – SW trending set of sub-parallel lineaments occurring in the pre-Aravalli pediplain country of Bhilwara area and the area east of Ajmer are significant fractures among which lineament No.6 connects Pb-Zn deposit of Zawar and Rajpura – Dariba mineralized belt. It is significant and needs detailed study for base metal mineralisation. The lineament No.7 which falls in the alignment of Pur – Banera and Sawar may also be a potential locii of base metal occurrence. The lineament No.8 which borders the Aravalli basin to the east of Kankroli and runs beyond Agucha (25º48’ : 76º45’) base metal prospect seems to have delimited the Aravalli basin to the east of Kankroli. The Phalet – Kotri and Agucha base metal mineralisation may be interrelated genetically as the lineament No.8 seems to be the extension of lineament No.1.

A number of intermediate and minor lineaments are found in the Aravalli basin, among which the intermediate lineament (No.9) found in Sallopet (23º09’ : 74º09’) area in the southern part of the basin is a well defined fault partly demarcating the intensely deformed

64 Lunavada (Aravallis) from the comparatively less deformed Aravalli sediments indicating its control over the tectonism of the sediments. The NW – SE trending intermediate lineament (No.10) which meets the Rakhabdev lineament near Rakhabdev warrants search for the ultrabasic suite of rocks. Similarly, lineaments No.11 and 12 are also significant in search of ultrabasic rocks.

In the areas occupied by the Delhi metasediments, the intermediate lineaments are mostly found in the northeastern part of the basin. These are mainly axial plane fractures of folds or faults associated with the Delhi orogeny. Among them the intermediate lineament No.13 is significant because of copper mineralisation in Khetri area. The other intermediate lineaments are mainly fractures and wherever these represent axial plane fractures of folds they form potential zones for base metal remobilization as in this area the mineralisation is mainly structurally controlled.

The Vindhyans of Rajasthan exhibit intermediate lineaments in plenty with varying orientation and distribution. The lineaments No.14 and 15 are faults associated with the Great Boundary Fault between Bundi and Indergarh. The NNW – SSE trending lineament (No.16) seems to be a significant lineament limiting the southwestern continuity of the Vindhyan basin beyond Sawai Medhopur. The other intermediate lineaments are fractures in Vindhyan sandstones.

A few scattered intermediate lineaments are found to traverse the Thar desert occupied by Paleozoic, Mesozoic and Cenozoic sediments with varying azimuth and frequency. A NE - SW trending lineament found northwest of Siwana ring structure (No.17) and another sub-parallel lineament (No.18) found northwest of Barmer seems to be sympathetic fractures of Luni – Sukri major lineament (No.VII). Similarly, a spectrum of NE – SW trending lineaments (No.19 to 22) are found between Luni – Sukri (No.VII) and the Chambal – Jamnagar (No.XIII) lineaments. Considering the earthquake epicenters in Luni lineament in Kutch area and considering their genetic interrelationship with lineament No.VII and XIII these intermediate lineaments may be earthquake prone zones. A few NW-SE trending lineaments (No.23 and 24) traverse the Thar desert in Bikaner area and are associated with Raisinghnagar – Tonk lineament system. The intermediate lineaments of Barmer, Jaisalmer and Bikaner area are also significant locations for groundwater prospecting (Ramasamy and Bakliwal, 1983a).

The Deccan trap country of southern Gujarat and Saurashtra exhibits a large number of lineaments with random orientation and prominence in ENE – WSW direction. The ENE – WSW system of lineaments found to the south of the Narmada river and NNE – SSW trending system of minor lineaments south of the Tapti river are dyke system intruded into the Deccan Trap and some of the ENE - WSW trending intermediate and minor lineaments in southern Saurashtra are the escarpments of different flows of Deccan Trap and a few are dyke swarms (Ramasamy, 1982, Departmental communication). The intermediate lineaments of Ahmedabad alluvial plains are very significant groundwater bearing zones and among which the intermediate lineaments (No.25 to 28) are related to adjoining major lineaments and may be the surface expressions of the underlying structures.

LINEAMENTS OF RAJASTHAN AND GUJARAT (INTERPRETED LANDSAT 1,2 & 3 IMAGERY)

LEGEND

MAJOR LINEAMENTS

AS FAULTS

AS BASIN MARGIN

INTERMEDIATE LINEAMENTS AS FAULTS

AS UNCLASSIFIED FRACTURES

MALANI VOLCANICS

POST-DELHIGRANITES (Erinpura, Siwana, Jalar Godhra)

VINDHYAN SUPER GROUP

SENDRA-AMBAJI, SYNOROGENIC GRANITES QUATERNARY AND RECENT

CENZOIC PROTEROZOIC DELHI SUPER GROUP TERTIARIES

DECCAN TRAP RIKHABDEV ULTRAMAFIC / OPHIOLITES

MESOZOIC ARAVALLI SUPER GROUP SEDIMENTARIES (Jaisalmer, Kutch, Himmatnagar)

UNTALA, GINGLA AND BERACH GRANITES BAP BOULDER BED / SANDSTONE ARCHAEOZOIC PALAEOZOIC BHILWARA SUPER GROUP MARWAR SUPER GROUP

The territorial waters of India extend into the sea to a distance GEOLOGY AFTER GSI of 12 nautical miles measured from the appropriate base line

66 MINOR LINEAMENTS

Rajasthan and Gujarat exhibit spectacular array of minor lineaments (<100 km) with random orientation. The minor lineaments are surface manifestations of lithologic contacts, axial plane fractures of folds, faults, dykes and mega joints. In the Aravalli, Delhi and Vindhyan Supergroup of rocks these lineaments are mostly tectonic features. In the Deccan volcanics in Saurashtra and the area between the Narmada and Tapti rivers the flow swarms and dykes swarms are manifested as minor lineaments (Ramasamy, 1985), Minor lineaments in the Ahmedabad alluvial plain may reflect the basement structure of the Mesozoic – Cenozoic sediments. In general, the minor lineaments form favourable zone for tapping groundwater (Ramasamy and Bakliwal, 1983).

CONCLUSIONS

A study of lineaments in western India, covering Rajasthan and Gujarat, reveals a spectacular array of lineaments of varying azimuth and distribution, traversing the rocks of different ages varying from Archaean to Recent.

Major lineaments assume utmost significance in the tectonic evolution of different sedimentary basins and in turn are correlatable with the igneous episodes. Some of the major lineaments even display signs of neotectonism. Jaisalmer – Barwani lineament is significant for search of groundwater and its related structures for hydrocarbons. Bharatpur - Mount Abu lineament aligns the geothermal springs. The Son – Narmada lineament acts as graben on global scale. Some of the major lineaments are significantly related to base metal mineralisation.

Numerous intermediate and minor lineaments are significant as they are surface features of faults, axial trace of folds and lithological boundaries. These lineaments contribute to the localization of the base metal, channelising the groundwater movements and acted as passages for magmatic emplacement.

References

Anon. (1981). Phase I report of Project CRUMANSONATA, Rep. (Unpublished) Geol. Surv. Ind. (W.R., F.S., 1979 – 81).

Anon. (1983).A few deep crustal fractures – New findings Geol. Surv. Ind. News (W.R.) 2(1): 6.

Bakliwal, P.C., Ramasamy, SM. and Ray, A.K. (1983). Lineament tectonics of Proterozoic basins of western India. Abs. Proc. Seminar on Proterozoic 1983, Lusaka, Zambia (April 1983).

Bakliwal., P.C. and Ramasamy, SM. (1983a). Basement structures in parts of Thar desert, western India – A study aided by Remote Sensing. Abs. Joint INDO – US Workshop on Arid zone Research, Central Arid Zone Research Instt. (CAZARI), Jodhpur (December, 1983).

Bakliwal, P.C. and Ramasamy, SM. (1983b). Occurrence of circular features in parts of Thar desert, Rajasthan, J. Geol. Soc. Ind. 26 : 225 - 228.

Bakliwal, P.C., Ramasamy, SM. and Sharma, S.B. (1980). On the migration of River Yamuna. J. Geol. Soc. Ind. 21 (9) : 461 – 463.

Billings, M.P. (1972). Structural Geology, 3rd ed. Prentice Hall Englewood Cliffs, New Jersey, 514 pp.

Blanchet, P.H. (1957). Development of fracture analyses as exploration method, Bull. Amer. Assn. Petrol. Geol. 48 (8) : 1748 – 1759.

Choubey, V.D. (1979). The Narmada lineament, India. Nature 232(28) : 38 – 40.

Coulson, A.L. (1928). Geology of Bundi State, Rajasthan, Rec. Geol. Surv. Ind. 60(2) : 164 – 203.

Crawford, A.R. (1978). Narmada – Son lineament of India traced into Madagascar. J. Geol. Soc. Ind. 19(4) : 144 – 153.

Dasgupta, S.K. (1975). A revision of Mesozoic Tertiary stratigraphy of the Jaisalmer basin, Rajasthan, India. Earth Sci. 2(1) : 77 – 94.

Datta, A.K. and Ravindra, R. (1980). Geology and mineral resources of Alwar district, Rajasthan, Mem. Geol. Surv. Ind. 110 : 1-137.

Ghosh, D.B. 1976. The Nature of Narmada – Son lineament, Geol. Surv. Ind. Misc. Pub. 34 (1): 119 – 132.

Gupta, S.N., Arora, Y.K., Iqbaluddin, Prasad Balmiki, Sahai, T.N. and Sharma, S.B. (1981). Lithostratigraphic map of Aravalli region – Southern Rajasthan and North Eastern Gujarat. Geol. Surv. India. (Published map, 1: 1,000,000).

Heman, P.J. (1961). Lineament analysis on aerial photographs ex7mplified in the North Surgeon Lake area, Calgary, Alberta, West Canadian research publication of geology and related sciences Series, 2(1): 1-20.

Hills, E.S. (1963). Elements of Structural Geology, John Wiley, New York, 483 pp.

Heron, A.M. (1936). The Geology of South Eastern Mewar. Mem. Geol. Surv. Ind. 68(1): 1- 120.

Hobbs, W.H. (1904). Lineaments of the Atlantic Border region, Geol. Soc. Amer. Bull. 15: 482 – 506.

68 Iqbaluddin, Prasad Balmiki, Sharma, S.B., Mathur, R.K., Gupta, S.N. and Sahait T.N. (1978). Genesis of the Great Boundary Fault of Rajasthan, India. Proc. Third reg. Conf. Geol. and mineral resources of South-East Asia, Bangkok, Thailand, p.145 – 149.

Kaiser, E.P. (1950). Structural significance of lineaments, Geol. Soc. Amer. Bull. 61 : 1475 – 1476.

Kelley, V.C. (1955). Regional tectonics of the Colorado plateau and relationship to the origin and distribution of uranium, Univ. New Maxico, Publ. Albuquerque, New Mexico., Geol. No.5 p.120.

Oldham, R.D., Datta, P.N. and Vredenberg, E.W. (1901). Geology of the Son Valley in the Rewa State and parts of the adjoining districts of Jabalpur and Mirzapur, Mem. Geol. Surv. Ind. 31 (1) : 1-178.

Pareek, H.S. (1984). Pre-Quaternary geology and mineral resources of north-western Rajasthan, Mem. Geol. Surv. Ind. 115.

Ramasamy, SM. (1985). Tectonics of Narmada lineament in Gujarat, Phase II report of Project CRUMANSONATA, Rep. (Unpublished) Geol. Surv. Ind. (F.S. 1982 – 84).

Ramasamy, SM. and Bakliwal, P.C. (1983a). Application of remote sensing in water resources survey in Thar desert, Rajasthan. Abs. National seminar on application of remote sensing techniques in geomorphology and hydrogeology. Andhra University, Waltair, (March, 1983).

Ramasamy, SM. (1983b). Groundwater targeting of Banded Gneissic Complex, Rajasthan through remote sensing. Abs. Proc. National Symp. on remote sensing in development and management of water resources, ISRO, Ahmedabad (Oct., 1983) p. 227 – 285.

Ray, A.K., Bakliwal, P.C. and Sharma, S.B. (1980). Lineament fabric of western India and its relation with genesis and localization of mineral deposits – A study aided by remote sensing, Proc. Seminar on applications of photo interpretation and remote sensing for natural resources survey and environmental analysis. Ind. Soc. Photo interpretation and Remote Sensing, Dehradun, 1980, p.52 – 56.

Reddy, A.G.B. and Ramakrishna, T.S. (1981). A geophysical study of the environment of base metal belts and related deep geological features to guide future exploration in Rajasthan. Rep. (Unpublished) Geol. Surv. Ind. Part 1 (P.S. 1976 – 81).

Sharma, S.B., Ray, A.K. and Bakliwal, P.C. (1982). A Study of Landsat lineament in relation to base metal occurrences in Rajasthan and Gujarat, Rec. Geol. Surv. Ind. 112 (7): 95 – 105.

Sonder, R.A. (1947). Discussion of shear patterns of earth’s crust. Amer. Geophy. Union Trans. 28 : 939 – 945.

Vrendenberg, E. (1906). Pleistocene movements in Indian Peninsula as indicated by irregularities of Narmada and other rivers in peninsular India. Rec. Geol. Surv. Ind. 33(1) : 33-45.

West, W.D. (1962). The line of Narmada Son Valleys, Curr. Sci. 31 : 143 – 144.

Wilson, J.T. (1948). Some aspects of geophysics in Canada with special reference to structural research in the Canadian shield – Part 2 - An approach to the structure of the Canadian shield. Amer. Geophy. Union Trans. 29: 691 – 726.