干旱区生态环境知识资源中心

Pollen record of an AMS radiocarbon dated lacustrine sediment profile underlying the Chandra peat deposit in Himachal Pradesh, yielded signatures of the globally reported Younger Dryas (YD) cold event. This report of the YD event in NW Himalaya, substantiated by mineral magnetic variations, also records significant wet and warm conditions prior to 12,880 cal yrs BP, depicting the Allerod interstadial preceding YD. The notable decrease in local (meadow) and regional (desert steppe) vegetation indicates major climate shift towards cold and dry conditions marking the onset of YD that intensified progressively till 11,640 cal yrs BP. The YD terminates with gradual reappearance of local and regional flora, indicating initiation of the Holocene wet and warm conditions. The pollen-inferred floristic changes and mineral magnetic variations suggest that in NW Himalaya the initiation and termination of the YD cold event was probably gradual.