Karewa Basin

Introduction:

The word Karewa in Kashmiri dialect means, “elevated table-land.” This term was first used by Godwin-Austin (1859) and 14later by Lydekker (1878) for an unconsolidated to semi – consolidated sand-clay-conglomerate sequence. These sediments occur as terraces, plateaus and mounds and rest over the Paleozoic-Mesozoic sediments of the Kashmir ‘basin’. De Terra and Patterson (1939) gave the first detailed account of these Quaternary sediments.

This compilation aims to evaluate the hydrocarbon potential of the Karewa Basin. Since the Paleozoic and Mesozoic sequences form the basement for the Karewa sediments, a short description of these is also included for a regional overview

 

The Kashmir Paleozoic-Mesozoic basin, spread over an area of about 5,200 sq km, lies in an intermontane valley formed by bifurcation of the Great Himalayan Range west of the Ravi River. It occupies an oval-shaped depression between the Pir Panjal Range in the SW and Zanskar Range in NE. The Paleozoic-Mesozoic succession rests over the crystalline rocks of the Salkhala. The Salkhala Crystalline together with the overlying Paleozoic-Mesozoic sequence has been tectonically transported as a thrust sheet on the back of the Panjal Thrust (= Main Central Thrust). To the NE, the Kashmir Basin is separated from the Spiti-Zanskar Basin by anticlinal upwarp constituted of the rocks known as the Kishtwar-Giabal-Nunkun-Suru Crystalline. In the Kishtwar area the quartzite sequence correlatable with ca 1900 Ma Rampur Group is exposed in a window, designated as the Kishtwar Window.

 

The Karewa sequence, occupying an area of about 2,500 sq km (Bhatt, 1989), rests over the folded Paleozoic-Mesozoic rocks of the Kashmir Basin in the Kashmir Valley floor, above the river alluvium. Most of the cultivated fields in the Kashmir Valley are situated on the Karewa sediments.