Petrography and Geochemistry of the Siwalik Sandstone and its Relationship to the Himalayan Orogeny
Abstract
The Siwalik molasse of post Eocene age, exposed along the western limb of the Makarwal Anticline (Surghar Range), has direct relationship with uplifting episodes of the Himalayan mountains present to their north. Detailed petrography of the sandstones together with chemical analyses of a few selected samples indicate varied mineral assemblages md major oxide proportions for Lower, Middle and Upper Siwalik. Thus the Siwalik molasse, which is hitherto classified on the basis of sandstone and shale proportions and the variations in their colour, may also be divided into different units on the basic of mineral assemblages and major oxide geochemistry, or at least these aspects can be used for subsurface correlation in limited domains of the Siwalik belt. Regarding the source rocks, carbonates were major contributor along with other rocks during the deposition of the Lower Siwalik. The presence of igneous and metamorphic rock fragments along with medium to high grade metamorphic minerals suggest crystalline rods as the source of the Middle Siwalik. Such a mineral assemblage has also been reported from the Middle Siwalik of India, indicating unroofing of crystallines on a regional scale in the source area. Common occurrence of zircon in the Middle Siwalik seems to have some relationship with recently reported radioactive mineralization. The Upper Siwalik seem to have been derived from the foredeep sediments (Lower and Middle Siwalik) which were involved in the southward prograding orogenic activity by the Pleistocene period.
References
Allen, J.R.L., 1965. Review of recent alluvial sediments. Sedimentology 5, 89-191.
Blatt, H., 1967. Original characteristic of clastic quartz grains. Jour. Sed. Petrol. 37, 401-424.
Blatt, H., and Christie, J.M., 1963. Undulatory extinction in quartz of igneous and metamorphic rocks and its significance in provenance studies of sedimentary racks. Jour. Sed. Petrol. 33, 559-579.
Bokman, J., 1952, Clastic quartz particles as indices of provenance. Jour. Sed. Petrol, 22, 17-24,
Calkins, J.A., Offield, T.W., Abdullah, S.K.M. & Ali, S.T., 1975. Geology of the Southern Himalayas in Hazara, Pakistan and adjacent areas. USS. Geol. Surv. Prof. Paper 716-c, 1-29.
Chaudhry, R.S., 1970. Petrography of the Siwalik Formation of the northwestern Himalayas. Bull. Indian Geol. Assoc. 3, 19-25.
Chaudhry, R.S., 1971. Petrogenesis of Cenozoic sediments of the northwestern Himalayas. Geol. Mag. 108, 43-48.
Chaudhry, R.S., 1972a. Developments in sediments of the northwestern Himalayas. Bull. Indian Geol. Assoc. 5, 23-32.
Chaudhry, R.S., 1972c. Petrogenesis of Siwalik sediments of the northwestern Himalayas. J. Geol. Soc. India. 13, 399-402.
Coleman, J.M., 1969. Brahmaputra River. Channel processes and sedimentation. Geology 3, 129--139.
Conolly, J.R., 1965. The occurrence of polycrystallinity and undulatory extinction in quartz in sandstone. Jour. Std. Petrol. 35, 116-135.
Farooqi, S.H., 1980. A critical study of Makerwal collieries development operations and proposals for development, Unpub. Rept. P.M.D.C.
Fok, RL., 1968. Petrology of Sedimentary Rocks. Hemphills, Austin, Texas, U.S.A.
Ganju, P.N. & Srivastava, VK., 1962. Occurrence of graywake in the Lower Siwalik, Simla Hills. Nature 194, 566-567.
Gill, W.D., 1951. The Stratigraphy of the Siwalik series in the Northern Potwar, Punjab, Pakistan. Quart. Jour. Geol. Soc. London 107, 375-394.
Johnson, G.D. & Vondra, LE., 1972. Siwalik sediments in a portion of the Punjab re-entrant the sequence at Haritalyangar, District Bilaspur, H.P. Himalayan Geol. 2, 118-144.
Keller, H.M., 1977. The magnetic polarity stratigraphy of an Upper Siwalik. sequence in the Pabbi Hills of Pakistan. Unpub. MS. thesis, Dartmouth College, Hanover, N.H., U.S.A.
Khakwal, A.D., 1969. Petrological study of the Upper Siwalik area near Chandigarh. Indian Mineral. 10, 210-214.
Krishnan, MS. and Aiyengar, N.K.N., 1940. Did the Indobrahm or Siwalik River exist? Geol. Sum. India Rec. 75, 6-24
Krynine, PD., 1937. Petrography and genesis of the Siwalik series. Amer. Jour. Sci. 34, 322-446.
Le Fort, P., 1975. Himalayas: The collided mange. Present Knowledge of the continental Am. Jour. Sci. 275-A, 1-44.
McMahon, C.A., 1883. On the microscopic structure of some sub-Himalayan rocks of Tertiary age. Rec. Geol. Surv. India 16, pt. 4.
McMurtry, M.G., 1980. Facies changes and time relationship dong a sandstone stratum, Middle Siwalik Group, Potwar Plateau, Pakistan. Unpub. M.S. thesis, Dartmouth College, Honover, N.H., U.S.A.
Oldham, R.D., 1893. A manual of geology of India. Govt. of India Publ., Calcutta.
Parkash, B. Sharma, R.P. & ROY, A.K., 1980. The Siwalik Group (molasse) Sediment by collision of continental plates. Sed. Geol. 25, 127-159.
Packham, G.H., 1954. Sedimentary structure as an important feature in the classification of sandstone. Am. J. Sci. 252, 466-476.
Pascoe, E.H., 1919, The early history of the Indus, Brahmaputtra, and Ganga. Quart. Jour. Geol. Soc. London. 75, 138-157.
Pascoe, E.H., 1964. A Manual of Geology of India, Vol. 3, Govt. of India Pub.
Pettijohn, F.J., Potter, P.E., & Siever, R., 1972. Sand and sandstone. New York, Springer-Verlag.
Pilgrim, G.E., 1919. Suggestions concerning the history of drainage of northern India. J. Asiatic Soc. Bengal N.S. 15, 9-15.
Powel, C. McA. & Conaghan, P.J., 1973. Plate Tectonics and the Himalayas. Earth plat. Sci. Lett. 20, 1-12.
prashad, B., 1941. The Indobrahm! or the Siwalik River. Geol. SW. India Rec. 74, 555-561.
Raju, A.T.R. and Dehadtai, P.V., 1962. Upper Siwalik sedimentation in parts of Punjab. Quart. Jour. 'Geol. Min. Met. Soc. Ind. 34, 120-127.
Raynolds, R.G.H., 1980. The Plio-Pleistocene structure and stratigraphic evolution of the Eastern Potwar Plateau, Pakistan. Upub. Ph.D. Thesis, Dartmouth College, Hanover, N.H., U.S.A.
Reineck, H.E., & Singh, I.B., 1975. Depositional Sedimentary Environments. Springer-Verlag, New York.
Sarwar, G. & DeJong, K.A., 1979. Arcs, Oroclines, syntaxes: the curvature of mountain belts in Pakistan. In Geodynamics of Pakistan, A. Farah and KA. DeJong eds. Geol. Surv. Pak. Quetta, 131-142.
Tandon, S.K., 1971. Pebble and gain fabric analysis of the Siwalik sediments around Ramnagar, Kumaun Himalaya. Himalayan Geol. 1, 59-74.
Thampson, D.B., 1970. Sedimentation of the Triassic (Scythian) red pebbly sandstone in the Cheshire Basin and its margins. Geol. J. 7, 183-216,
Visser, C.F., and Johnson, G.D., 1978. Tectonic control of Late Pliocene molasse sedimentation in a portion of the Jhelum re-entrant, Pakistan. Geol. Rundsch. 67, 15-37.
Wadia, DM., 1932. Tertiary geosyncline of northwest Punjab and history of quaternary earth movements and drainage of the Gangetic Trough Quart. J. Geol. Min. Metal. Soc. India 4, 69-96.
