Changing pattern of vegetation in the intermontane basin of Kashmir since 4 Ma: a palynological approach

Abstract

The Upper Karewas are devoid of biomass potential and hence no palynostratigraphy could be established. In contrast, Lower Karewas are both quantitatively and qualitatively rich in biota. The major areas of study include Dubjan, Hirpur, Krachipathra, Ningle Nullah, Laredura, Liddarmarg, Butapathri, Wapjan, etc. Dubjan, supposedly the basal part of the Karewa sequence, overlies unconformably the Panjal volcanics and Hirpur overlies the Dubjan. Recent palaeomagnetic studies suggest that these sediments span late Gilbert to middle Matuyama magnetic polarity ranging in age between 3.5 to 2.0 Ma. Wapjan is the uppermost pan of the Lower Karewa and falls between late Matuyama to early Bruhnes ranging in age between 0.75 to 0.70 Ma.

Palynological and palaeobotanical investigations carried over a large number of exposures have revealed that there is no unanimity in vegetation all through the Karewa deposits, instead, a variety of vegetation types has been recorded in time and space indicating their development under different circumstances. The vegetation met here varies from typical subtropical to desertic alpine type. The climate has not been static for a long period rather reciprocity in the climate has been recorded which has been deciphered from vegetal signatures left by the nature. Post-glacial sediments from the lake basin in the valley have also been investigated, which reveal three-fold vegetational development reflecting on three-fold climatic evolution.