QUATERNARY PALAEOLAKES IN KUMAUN LESSER HIMALAYA - FINDS OF NEOTECTONIC AND PALEOCLIMATIC SIGNIFICANCE

Movements in the geologically recent time on the North Almora Thrust; South Almora Thrust; on related subsidiary thrusts and faults caused b lockade of the river Kosi west of Almora and of the Thuli Gad east of Pithoragarh in the Kumaun Lesser Himalaya. The fault movements resulte d in the formation of lakes that have since vanished due to revival of neotectonic movements. Stretching more than 7 km in length, these pal aeolakes are presumably the biggest so far known in Kumaun. The lacust rine deposits comprising carbonaceous clays in Pithoragarh, and silty ferruginous clay capping the fluviolacustrine deposits in the Kosi val ley promise to hold important palaeoclimatic clues. Preliminary radioc arbon dating of carbonaceous clay, rich in charcoal fragments, indicat es that the Wadda lake at Pithoragarh was formed about 44,000 years BP and, probably, lasted until about 2000 years BP.