PETROLOGY & GEOCHEMISTRY OF PANJAL VOLCANICS IN POONCH, MUZAFFARABAD AND KAGHAN VALLEY

Abstract

The project AJK Earth I 33 entitled" Petrology and Geochemistry of the Panjal volcanics in Poonch,Muzaffarabad and Kaghan was granted by PSF in March,1988. Work was launched in May 1988 and continued upto October 1990.It was interrupted due to revi?'s observations for about eleven months. After the release of funds the research work was restarted in October 1991 and ended in March 1992. Anyhow during the entire life of the project four earth scientists remained busy for its completion. Geological mapping was carried out right from Kahuta( in Poonch now Bagh District ),Muzaffarabad (from Chamm in Jhelum Valley to Kaghan watershed) to Kaghan Valley (in NWFP), that is the entire exposure in Azad Kashmir and Kaghan Valley, Pakistan. The geological mapping was carried out on 1: 50,000 scale and the maps are reduced to handy presentable form. A composite map of the entire exposures and surrounding rocks is also presented on 1: 250,000 scale as a requirement of the project. Thus a new and detailed geological map of the Panjal volcanics is presented for the first time. Five section were measured, to establish stratigra,ghy of the Panjal volcanics in particular. Geology of the entire area is reinterpretted stratigraphy,structure,geochemistry and magma type. The occurrence of of in terms

Hazara Kashmir Syntaxis of Western Himalaya around project area form a great anticlinal structures with extensive imbrication. The area remained uplifted three times forming late Cambrian unconformity ( with bauxite/laterite, phosphorite and cherty clasts) which merged with the Late Cretaceous Pre-Paleocene unconformity of Muzaffarabad and Kotli areas. THe second Paleozoic unconformity is between Dogra slate and Gondwana Gr?up in Kahuta area of Pre-Carboniferous times. The third unconformity is between Kuldana Formation and Murree Formation. The major structural features which dominate all along the eastern limb of the Hazara Kashmir Syotaxis are the Main Boundry Thrust (H.B.T.) and the Panjal Thrust and not the Main Central Thrust( H.C.T.) as

indicated by Greco( 1989) In our views the M.C.T. occurs near Sharda and joins the M.C.T. of Chaudhry & Ghazanfar ( 1990) near Battal in Kaghan Valley. 136 petrographic analyses have helped a lot to understand the Panjal volcanic rocks now as regards to major and minor minerals towards their alteration and origin. Geochemistry of 111 Panjal volcanic rocks reveal that the rocks are tholeiitic. The tholeiitic character of these rocks represent that the Panjal magma was derived by extensive partial melting of the mantle material. Extensive partial melting of the mantle material is further supported by the absence of the ultramafic members and very low values of Ni and Co in the Panjal volcanics. The plots of the Panjal volcanics on discriminant diagrams for the tectonic setting indicate that the lava erupted in a submarine to continental conditions. The eruption of the Panjal lava occured in two phases. First of all agglomerates were formed while with the opening of geofracture a shallow ocean basin was developed along with deposition of pillow basalts with bedded chert,jasper and intertrappean limestone. Small lensoid bodies and showings of lead,zinc and coppe? have been fou?d so far associated with Panjal volcanics near Jhugian and Bandi Gorsian.