Preliminary Geology And Petrography Of Swat Kohistan

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Age and Correlation : The complex, covering many thoi~snnrl Square miles, from Afghanistan to southern Cilgi t Anency. It has been coilsidered, lvith reservatioas, to be oldnr tho11 the Siluro-Dcvo~~~ rocks of the Lower <strong>Swat</strong> - Buner Schistose Group by Martin ct ol. (1%2) nnd ihvias (1964). Bskr alld Jac~rson (1964) have shown theso rocks to be Preet~mbrinn in age. It were the quartz diorites of the complex, apparently, that Mat8sushitl.z (1965, ; + p. 84) called gmnite, snd correlated with tho granites of Shungi Go1 (Middle to Barly Mesozoic) of Cilgit Agency. Jan (1070, p. 30) ~loted that tho llorites *xtend, at least, up lo ten miles lo t'he east of Chilns and can he correlated ~17ith t8hose of the Naaga Parbnt massir. Tlie latter are gerleticnlly rclnted to the Creto-Eocene volcanic rocks of IiasEiin ir usc2 may, thus, Lo contc; mporczneous with, or slightly younger, than the volca~iics (Miseh, 1949, TI. 216). On these ' grounds, Jam (1970) considered the norites to havo been et~~plncecl during the : earliest phases of the I3irnnlayan orogeny and Middle to Lt1t.o Cretacc-ous ill age, A pegmatite hornblende near Balirtiin has been dulecl to he 67 PI. y. by IC/Ar mcthod (Jan and Kempe, in preparation). Since the pgmcrtit ecr nre consiclered by them to be the final products of the igneous and metamorpltic qhode which produced the basic series of Upper <strong>Swat</strong>, EL Late Cret:mous ago can bc assigned 1 to the complex. The Utwr Volcanics. Grey, green, red and, rarely, white volcaaic rooks cover n large area to the northwest of Kalam. To the oast they extend in Ushu Vnlley and to the west in Dir. The Utror village is surrounded on all fiidcs by volcanic exposures. Mottling of various colours, particularly the red and green, is conspicuous in many places. In these, larger volcanoclslrsts lie in s matrix aft^ different colour. In the red and green ones, the matrix is nearly always of green colour. This may suggest a, higher frequency of the reddish matarial in tliu early atagos of the volcanic activity. The green mass appeare to be more readily altered than the red; the colour of the formor is mainly due to secondary chl.orito and epjdote, and that of the latter due to oxidized iron ore granules. In general, volcanoclastic rocks are more abundant than. flows. They may be fine-grained, homogen~ons tufls or, as is often the cam, eorn~oscd of larger fragments set in a tuffaceous or lava matrix (Pig. 2). Some aro a confused mixture of pyroclaetios arid lava; the former &ay be over 50% in the form of frngmente coarser than ash. The fragments may be angular or rounded, and up to a foot
Fig. ll. Pegmatite near Brhrtn with giant horn11 contain coarae felwic inclrraions. Voleanic breccia near Bankhwar a 1o11p road wle.
Page 1 and 2: Ecol. Bull. Univ. Peshawar, Val. 6,
Page 3 and 4: narrow gorges are formed rt some pl
Page 5 and 6: Dewangar Granite ? Middle Porphyrit
Page 7 and 8: They appear; to have been gradually
Page 9 and 10: para.lle1 to foli~.tion. Moxt of th
Page 11: Local, small intrusions of granites
Page 15: preeence of chlorite, epidote, and
Page 18 and 19: some breccies to the southwest of K
Page 20 and 21: The rocks to the southwest of Dewan
Page 22 and 23: The roclrs are generally in the for
Page 24 and 25: The rocks are mediam-grained, hypid
Page 26: . development of a clinoampi~ibole
Page 29 and 30: ank do not extend on the eastern si
Page 31 and 32: Hovever, there are a few rooks in w
Page 33 and 34: most. The main metallic minerals no
Page 35: BIARTIN, N.R., SIDDIQUI, S.F.A. and

Preliminary Geology And Petrography Of Swat Kohistan

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