SEDIMENTARY FACIES ANALYSIS OF NAGRI FORMATION, KASHMIR BASIN, SUB-HIMALAYAS, PAKISTAN
Journal: Pakistan Journa l of Geology (PJG)
Author:Noman Abbasi, Muhammad Sabir Khan, Muhammad Saleem Mughal, Muhammad Yasin
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Nagri Formation, the subject of this study, lies in northeastern part of Kashmir basin, Pakistan along a belt of about 250-kilometer square. The Nagri Formation forms alternate beds of sandstone, claystone and/or mudstone. These are molasse deposits formed during the Himalayan orogeny and are early Pliocene in age. The Formation consists of six sedimentary facies: para-conglomerate (N1) comprised of massive conglomerates with the absence of grading and matrix supported fabric of clayey sand; ortho-conglomerate (N2) are normal graded conglomerates and are poorly sorted having clasts supported fine to very coarse grain matrix; massive sandstone (N3) is composed of medium to coarse sized grains, contains massive sandstone beds and is poorly sorted with scattered pebbles at some locations; cross bedded sandstone (N4) consist of to medium to coarse textured, cross bedded sandstone; parallel laminated sandstone (N5) comprising fine to coarse grained and poorly sorted sandstone beds with thin parallel laminations; and mudstone (N6) comprised of massive claystone’s, siltstones and mudstone that lack any noticeable sedimentary structure. The conglomerates, sandstone and mudstone/siltstone/claystone facies are stacked in ascending order and are deduced as a sequence of channel bar and floodplain or over bank deposits confined to a braided fluvial system.