Chsmistry And Petrography Of The Sillai Patti Corbonate Complex ...

The Sillai Patti carbonatite shows abundant evidcnce of granulation in calcite and the
development of metamorphic minerals such as epidotc. This would suggest that these rocks
have suffered some post-consolidation metamorphism. Thc nature of metamorphic effects has
not been the main purpose of this study. However, mctitmorphosed nature of this carbonatite is
mply indicated (John Gittins, written communication). If such is the casc, the K-Ar data,
reported by Le Bas et al. (1987) may require some rcinlerpretation.
Le Bas et al. (1987) rcported a Carboniferous age for ijolite from Koga area. Panjal
volcanics of Pcrmo-Carboniferous age from Kashmir in North Pakistan have been interpreted
by Butt et al. (1985) to represent basaltic rocks associated with an incipient ocean possibly
related to rifting of the Indian continent. Carwford (1974) considered the Panjall traps in Kashmir,
Rajmahal traps of West Bengal and Bihar, and Sylhct traps of Bangladesh to
ated with rifting of Gondwanaland. Thcse tensional cvcnts favourably coincide with a Carboniferous-Permian
carbonatitic and alkaline magmatism near Koga. In view of the above, and the
metamorphosed nature of Sillai Patti complex, it is possiblc that the alkaline and carbonatitic
magmatism belongs to a tensional event during the brcakup of Gondwanaland. Further gsochronological
data is rcquircd to substantiate this intcrprctation.
Acknowledgements: Critical reading of the manuscript by Dr. Ihsanullah Mian and Dr. M.
Qasim Jan helped improve the manuscript. M. Barkatullilh of NCE in Geology, University of
Peshawar, is thanked Tor the microprobe analysis of thc amphibole.
Ashraf, Ma & Chaudhry, M,N., 1977. A note on the discovery of carbonatite from Malakand district. Geol. Bull,
Punjab Univ. 14, 91-94.
Rarrh, T.F,W, & Ramberg, L.B., 1966. Thc Pen circular cornplcx. Tn: Carbonatites (03,'httle & J, Gittins eds.).
Wiley Intersciencc, New York.
Butt, KA., Shah, Z., Shah, S. & Qndir, A., 1986. Gcolagy and Uranium mineralin~tion associated with Ilum granitic
complex and associa~cd mctasediments. Unpub, report AISMC IIRD, Pcshawar.
, Chaudhry, M,N. & Ashraf. M., 1985. Evidence of an incipient Palacomic ocean in Kashmir, Pakistan,
Kashmir Jour. Gcol, 3,87-102.
Chaudhry, M.N,, Ashraf, M., IIussain S.S. & Iqbd, M,, 1976. Caology and petrology of Malakand and part of Dir.
Geol. Bull. Punjab Univ. 12, 17-39.
Crawford, A.R., 1974. The Indus suture line, thc Hamalaya, Tibet and Gondwanaland. Geol. Mag, 111, 369-383.
Deer, W.A., Iiowie, R.A, & Zussrnan J., 1962. Rock-forming Minerals, Vol. 5. Longman, London,
Goldsmith, J.R., Graf, D.L, Witters, J. & Northrop, D.A., 1962, Studics in the systm CaCO, - MgCO, - FeCO,.
Jour. Geol. 70, 659-688.
Jan, M.Q., Asif, M. & Tahirkhcli, T., 1981. Thc geology and pcttography of Tarbcla alkaline complex. Geol. Bull.
Univ. Peshawar 14, 1-28.
, Kamal, M. & Qureshi, A.A., 1981. Petrography of Loe-Shilman carbonatite cornplcx, Khybcr Agency. Gcol.
Bull. Univ. Pcshawar 14, 29-43.
Kempe, D.R.C., 1983. Alkaline granites, syenites and associated rocks of the Peshawar plain Alkaline igneous province,
NW Pakistan. In: Granites of Himalaya, Karakoram and Hindukush (F.A. Shams ed.). Punjab Univ.,
Lahore, 143-1 70.
Khattak, M.U.K., Ahmed, I., Ahmed, J. & Ahmed, A., 1984. Carbonatite body near Khungai, Rustam area, District
Mardan, North Pakistan. Geol. Bull, Univ. Peshawar 17, 174-175.