What is karewas? Formation of karewas

The Kashmir valley is an oval-shaped basin, 140 km long and 40 km wide, trending in the NNW–SSE direction. It is an intermountain valley fill, comprising of unconsolidated gravel and mud. A succession of plateaus is present above the Plains of Jhelum and its tributaries. These plateau-like terraces are called ‘Karewas’ or ‘Vudr’ in the local language. Despite continuous erosion since millions of years, more than half of the valley is still occupied by the Karewa.

Thus, Karewas are lacustrine deposits (deposits in lake) in the Valley of Kashmir and in Bhadarwah Valley of the Jammu Division. These are the flat topped mounds that border the Kashmir Valley on all sides. They are characterized with fossils of mammals and at places by peat.

Karewas were formed during the Pleistocene Period (1 million years ago), when the entire Valley of Kashmir was under water. Due to the rise of Pirpanjal, the drainage was impounded and a lake of about 5000 sq. km area was developed and thus a basin was formed. Subsequently, the lake was drained through Bramulla gorge. The deposits left in the process are known as karewas. The thickness of karewas is about 1400 m.

The karewas have been elevated, dissected and removed by subaerial denudation to be in the present position.

The Karewa deposits in the Kashmir valley have been conventionally divided into two stages, lower and upper, representing argillaceous and arenaceous facies respectively. The upper Karewas are less fossiliferous than the lower Karewas. The entire belt touching the foothills of the Pirpanjal represents the lower Karewas, which has been exposed to the rivers starting from the south such as Veshav, Rembiara, Romushu, Dodhganga, Shaliganga, Boknag nar and Ningli. Lower Karewa sections at Aharbal, Anantnag, Arigam, Baramulla have been exposed by these rivers.

The rest of the Karewa sediments occupy the middle of the entire flank of the valley, including Pampore, Srinagar, Burzuhom, Dilpur, Pattan, Parihaspora, and parts of Baramulla District. These represent upper Karewas of the valley. The late Cenozoic deposits exposed in the Kashmir valley assume special significance as they are extensively fluvioglacial, fluvial, lacustrine and eolian in origin. The age determination of a Karewa is based on the correlation between Karewa and Shiwalik fauna from India and Pakistan. As far as the age of Karewas is concerned, the lack of chronological control has impeded the development of a detailed reconstruction of the Karewas depositional history in the intermountain basin of the valley.

Source-India: Environment & Resources by K. Siddhartha

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