Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T12:46:15.308Z Has data issue: false hasContentIssue false

Collision zone between the Kohistan arc and the Asian plate in NW Pakistan

Published online by Cambridge University Press:  03 November 2011

C. J. Pudsey
Affiliation:
Department of Geology, The University, Leicester LEI 7RH, England
M. P. Coward
Affiliation:
Department of Geology, Imperial College, Prince Consort Road, London SW7 5BP, England.
I. W. Luff
Affiliation:
Department of Geology, The University, Leicester LEI 7RH, England.
R. M. Shackleton
Affiliation:
Department of Earth Sciences, The Open University, Walton Hall, Milton Keynes, MK43 7BB, England.
B. F. Windley
Affiliation:
Department of Geology, The University, Leicester LEI 7RH, England.
M. Q. Jan
Affiliation:
Centre of Excellence in Geology, University of Peshawar, Peshawar, N.W.F.P., Pakistan.

Abstract

This paper describes the suture zone between the Asian plate and the accreted Kohistan island arc in the Chitral district of NW Pakistan.

The southern part of the Asian plate consists of two tectonic units separated by the N-dipping Reshun fault. The northwestern unit comprises Devonian carbonates and quartzites overlain by Devonian to Permian shales and slates with some limestones (Lun shales). Its structure is complex with S-verging thrusts and isoclinal folds. Along the Reshun fault, the relatively undeformed Reshun Formation may represent molasse. The central unit includes N-dipping Upper Palaeozoic slates and quartzites (Darkot Group), probably faulted against an antiformal tract of slates, schists derived from a volcanic assemblage and Cretaceous limestones (Chitral slate, Koghozi greenschist, Krinj and Gahiret limestones). Asian plate sediments are intruded by granitic and granodioritic plutons, variably deformed and locally porphyritic.

The Northern suture melange of volcanic, sedimentary and serpentinite blocks in a slate matrix separates the Asian plate from the southeastern unit, the Kohistan arc. This comprises Cretaceous volcanic rocks with some sediments (Shamran Volcanic Group, Drosh, Purit and Gawuch Formations) intruded by aphyric diorites, tonalites and granites. These intermediate plutonic rocks pass southwards into a mafic layered complex and amphibolites representing deep levels of the arc. The volcanic rocks and sediments dip to the N and have a horizontal lineation. The structural history of southern Asia and Kohistan is consistent with an originally curved Northern suture: motion of the arc was initially to the NE relative to Asia and subsequently to the NW.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1985

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bard, J. P., Maluski, H., Matte, P. & Proust, F. 1980. The Kohistan sequence: crust and mantle of an obducted island arc. In Tahirkheli, R. A. K., Jan, M. Q. & Majid, M. (eds) Proceedings of the International Commission on Geodynamics, 8794SPEC ISSUE GEOL BULL UNIV PESHAWAR 13.Google Scholar
Brindley, G. W. & Brown, G. 1980. Crystal structures of clay minerals and their X-ray identification. MONOGR MINERAL SOC LONDON 5.Google Scholar
Brookfield, M. E. 1980. Reconnaissance geology of the Hushe and Saltoro–Kondus river valleys, Karakorum Mountains, Kashmir, Pakistan. REND ACCAD NAZ LINCEI 69, 248–53.Google Scholar
Calkins, J. A., Jamiluddin, S., Bhuyan, K. & Hussain, A. 1981. Geology and mineral resources of the Chitral-Partsan area, Hindu Kush range, N. Pakistan. U S GEOL SURV PROF PAP 716–G.Google Scholar
Casnedi, R., Desio, A., Forcella, F., Nicoletti, M. & Petrucciani, C. 1978. Absolute age of some granitoid rocks between Hindu Raj and Gilgit river (W. Karakorum). REND ACCAD NAZ LINCEI 64, 204–10.Google Scholar
Coward, M. P., Jan, M. Q., Rex, D., Tarney, J., Thirlwall, M. & Windley, B. F. 1982. Geotectonic framework of the Himalaya of N. Pakistan. J GEOL SOC LONDON 139, 299308.CrossRefGoogle Scholar
Coward, M. P., Windley, B. F., Broughton, R. D., Luff, I. W., Petterson, M. G., Pudsey, C. J., Rex, D. C. & Asif Khan, M. 1985. Collision tectonics in the NW Himalayas. In Coward, M. P. & Ries, A. C. (eds) Collision Tectonics, 203219. SPEC PUBL GEOL SOC LONDON 19.CrossRefGoogle Scholar
Desio, A. 1959. Cretaceous beds between Karakorum and Hindu Kush ranges (Central Asia). RIV ITAL PALEONT STRAT 65, 221–9.Google Scholar
Desio, A. 1963. Review of the geologic “Formations” of the western Karakorum (central Asia). RIV ITAL PALEONT 69, 475501.Google Scholar
Desio, A. 1964. Geological tentative map of the western Karakorum, 1:500,000. Milan: Istituto di Geologia.Google Scholar
Desio, A. 1966. The Devonian sequence in Mastuj valley (Chitral, NW Pakistan). RIV ITAL PALEONT 72, 293320.Google Scholar
Desio, A. 1975. Some geological notes and problems on the Chitral valley (NW Pakistan). REND ACCAD NAZ LINCEI 58, 17.Google Scholar
Desio, A. 1980. Geology of the upper Shaksgam valley. Italian expeditions to the Karakorum (K2) and Hindu Kush, Scientific Reports, III (4). Leiden: Brill.Google Scholar
Desio, A. & Martina, E. 1972. Geology of the upper Hunza valley, Karakorum, W. Pakistan. BOLL SOC GEOL IT 91, 283314.Google Scholar
Desio, A., Tongiorgi, E. & Ferrara, G. 1964. On the geological age of some granites of the Karakorum, Hindu Kush and Badakhshan (Central Asia). REP 22ND INT GEOL CONGR 11, 479–96.Google Scholar
Fermor, L. L. 1922. General report for the year 1921. REC IND GEOL SURV 54.Google Scholar
Flügel, E. 1982. Microfacies analysis of limestones. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Forcella, F. 1978. Short notes on Tirich Mir geology (Hindu Kush range). REND ACCAD NAZ LINCEI 65, 307–12.Google Scholar
Hayden, H. H. 1915. Notes on the geology of Chitral, Gilgit and the Pamirs. REC IND GEOL SURV 45, 271335.Google Scholar
Ivanac, J. F., Traves, D. M. & King, D. 1956. The geology of the northwest portion of the Gilgit agency. REC GEOL SURV PAKISTAN 8, 326.Google Scholar
Johnson, B. D., Powell, C. McA. & Veevers, J. J. 1976. Spreading history of the eastern Indian Ocean and Greater India's northward flight from Antarctica and Australia. BULL GEOL SOC AM 87, 1560–6.2.0.CO;2>CrossRefGoogle Scholar
Klootwijk, C. T. & Conaghan, P. J. 1979. The extent of Greater India, I. Preliminary palaeomagnetic data from the Upper Devonian of the E. Hindukush, Chitral (Pakistan). EARTH PLANET SCI LETT 42, 167–82.CrossRefGoogle Scholar
Norin, K. 1974. The ‘black slates’ formations in the Pamirs, Karakoram and western Tibet. ATTI DEI CONVEGNI LINCEI 21, 245–64.Google Scholar
Pascoe, E. H. 1923. General report for the year 1922. REC IND GEOL SURV 55.Google Scholar
Pascoe, E. H. 1924. General report for the year 1923. REC IND GEOL SURV 56.Google Scholar
Petterson, M. G. & Windley, B. F. 1985. Rb–Sr dating of the Kohistan arc-batholith in the Transhimalaya of N. Pakistan, and tectonic implications. EARTH PLANET SCI LETT 74, 4557.CrossRefGoogle Scholar
Pudsey, C. J., Schroeder, R. & Skelton, P. W. 1986. Cretaceous (Aptian–Albian) age for island arc volcanics, Kohistan, N. Pakistan. In Gupta, V. J. (ed.). Recent researches in geology. Palaeontology: stratigraphy and structure of Western Himalayas. Delhi: Hindustan Publishing Co.Google Scholar
Reed, F. R. C. 1922. Devonian fossils from Chitral and the Pamirs. PALAEONT INDICA 6(2).Google Scholar
Reed, F. R. C. 1925. Upper Carboniferous fossils from Chitral and the Pamirs. PALAEONT INDICA 6(4).Google Scholar
Stauffer, K. W. 1975. Reconnaissance geology of the central Mastuj valley, Chitral State, Pakistan. U S GEOL SURV OPEN FILE REPORT 75–556.CrossRefGoogle Scholar
Tahirkheli, R. A. K. 1979. Geology of Kohistan and adjoining Eurasian and Indo-Pakistan continents, Pakistan. In Tahirkheli, R. A. K. & Jan, M. Q. (eds) Geology of Kohistan, 130. SPEC ISSUE GEOL BULL UNIV PESHAWAR 11.Google Scholar
Tahirkheli, R. A. K., Mattauer, M., Proust, F. & Tapponnier, P., 1979. The India Eurasia suture zone in northern Pakistan: synthesis and interpretation of recent data at plate scale. In Farah, A. & Dejong, K. A. (eds) Geodynamics of Pakistan, 125–30. Quetta: Geological Survey of Pakistan.Google Scholar
Talent, J. A., Conaghan, P. J., Mawson, R., Molloy, P. D. & Pickett, J. W. 1982. Intricacy of tectonics in Chitral (Hindu Kush): faunal evidence and some regional implications. In Himalayan geology, sect. IIA, 77101. GEOL SURV INDIA MISC PUBL 41.Google Scholar
Trommsdorff, V., Dietrich, V. & Honegger, K. 1982. The Indus Suture Zone: paleotectonic and igneous evolution in the Ladakh-Himalayas. In Hsü, K. J. (ed.) Mountain building processes, 213–9. London: Academic Press.Google Scholar