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The petrology of the Warsak alkaline granites, Pakistan, and their relationship to other alkaline rocks of the region

Published online by Cambridge University Press:  01 May 2009

D. R. C. Kempe
Affiliation:
Department of Mineralogy, British Museum (Natural History), London SW7 5BD

Summary

A suite of Tertiary alkaline porphyritic microgranites and hybrid and peralkaline granite from northwest Pakistan is described, with six rock analyses (five of them new). The microgranites, an earlier group of which some contain garnet, have undergone metamorphism, lacking in the granites. The microgranites are shown to be precisely similar to those from the Shewa–Shahbazgarhi area, for which four analyses (two of them new) are presented, and related to a third group from Tarbela. The mineralogy of the rocks is discussed, with seven new analyses of aegirine, riebeckite, ferrohastingsite and astrophyllite, and X-ray determinations of the feldspar compositions. The granites are considered to be related to the undersaturated syenites and associated rocks of Koga, and a petrogenetic scheme for the alkaline province is presented, with a K/Ar age determination, tentatively deriving the source magma (quartz trachytic) from a Himalayan tholeiite.

Type
Articles
Copyright
Copyright © Cambridge University Press 1973

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References

Ahmad, M., All, K. S. S., Khan, B., Shah, M. A. & Ullah, I. 1969. The geology of the Warsak area, Peshawar, West Pakistan. Geol. Bull. Univ. Peshawar 4, 4478.Google Scholar
Bakr, M. A. & Jackson, R. O. 1964. Geological map of Pakistan. Geol. Surv. Pakistan.Google Scholar
Borley, G. D. 1963. Amphiboles from the Younger Granites of Nigeria. Part I. Chemical classification. Mineralog. Mag. 33, 358–76.Google Scholar
Coulson, A. L. 1936. A soda-granite suite in the North-West Frontier Province. Proc. Natn. Inst. Sci. India 2, 103–11.Google Scholar
Hamilton, D. L. & Mackenzie, W. S. 1965. Phase-equilibrium studies in the system NaAlSiO4 (nepheline)–KAlSiO4 (kalsilite)–SiO2–H2O. Mineralog. Mag. 34, (Tilley vol.), 214–31.Google Scholar
Jacobson, R. R. E., Macleod, W. N. & Black, R. 1958. Ring-complexes in the Younger Granite Province of Northern Nigeria. Mem. geol. Soc. Lond. 1, 172.Google Scholar
Jan, M. Qasim & Kempe, D. R. C. 1973. The petrology of the basic and intermediate igneous rocks of upper Swat, Pakistan. Geol. Mag. 110 (3), 285300.Google Scholar
Kempe, D. R. C. & Deer, W. A. 1970. The mineralogy of the Kangerdlugssuaq alkaline intrusion, East Greenland. Meddr. Grønland 190, nr. 3, 195.Google Scholar
Kempe, D. R. C., Deer, W. A. & Wager, L. R. 1970. The petrology of the Kangerd-lugssuaq alkaline intrusion, East Greenland. Meddr. Grønland 190, nr. 2, 149.Google Scholar
Kempe, D. R. C. & Jan, M. Qasim. 1970. An alkaline igneous province in the North-West Frontier Province, West Pakistan. Geol. Mag. 107, 395–8.Google Scholar
Khan, A. B., Shah, Z. H. & Naeem, S. M. 1970. Geology of the Ghundai Sar and vicinity, Jamrud, Khyber Agency. Geol. Bull. Univ. Peshawar 5, 115–30.Google Scholar
Le Maitre, R. W. 1962. Petrology of volcanic rocks, Gough Island, South Atlantic. Bull. geol. Soc. Am. 73, 1309–40.Google Scholar
Martin, N. R., Siddiqui, S. F. A. & King, B. H. 1962. A geological reconnaissance of the region between the Lower Swat and Indus Rivers of Pakistan. Geol. Bull. Panjab Univ. 2, 114.Google Scholar
Morse, S. A. 1969. Syenites. Rep. Dir. geophys. Lab. Carnegie Instn. 67, 112–20.Google Scholar
Nockolds, S. R. 1954. Average chemical compositions of some igneous rocks. Bull. geol. Soc. Am. 65, 1007–32.CrossRefGoogle Scholar
Siddiqui, S. F. A. 1965. Alkaline rocks of Swat, Chamla. Geol. Bull. Panjab. Univ. 5, 52.Google Scholar
Siddiqui, S. F. A. 1967. Note on the discovery of carbonatite rocks in the Chamla area, Swat State, West Pakistan. Geol. Bull. Panjab Univ. 6, 85–8.Google Scholar
Siddiqui, S. F. A., Chaudhry, M. N. & Shakoor, A. 1968. Geology and petrology of the feldspathoidal syenites and the associated rocks of the Koga area, Chamla valley, Swat, West Pakistan. Geol. Bull. Punjab Univ. 7, 130.Google Scholar
Tuttle, O. F. & Bowen, N. L. 1958. Origin of granite in the light of experimental studies in the system NaAlSi3O8-KAlSi3O8-SiO2-H2O. Mem. geol. Soc. Am. 74, 153 pp.Google Scholar