C01_05

Application and potential of AMS based Radiocarbon Dating from Aeolian and Lacustrine Deposits for Reconstructing Quaternary Glaciation in the Himalaya

Kumar P¹, Gaur S¹, Sharma M², Kumar P³, Chopra S³

¹Department Of Geography, Faculty Of Physical Sciences, Bhiwani, India, ²Jawaharlal Nehru University, New Delhi, India , ³Inter University Accelerator Centre, New Delhi, India

The Himalayan glaciers have waxed and waned as a result of cyclic glacial and inter-glacial phases during the Quaternary period and contributed to the formation of mesmerising and complex landforms. The precise construction of chronology of these landforms can work as a yardstick to perfectly determine phases of glaciation and deglaciation. The timing and extent of the Quaternary glaciation in the Himalayan region have been inadequately reconstructed due to inaccessibility, a dynamic climatic system formed by a complex interaction of mid-latitude westerlies and the Indian Summer Monsoon (ISM), complex assemblages of Quaternary landforms, and resettling of glacial genesis as a result of a high energy environment and steep gradient, and the lack of high resolution dating techniques based on comprehensive glacial chronologies. Mostly, OSL and CRN (10Be and 26Al) based surface exposure dating techniques have been used to construct the quaternary glaciation due to the unavailability of organic material for radiocarbon dating. However, both quaternary dating techniques have their own limitations, i.e., partial bleaching with OSL and inheritance with CRN. However, the development of AMS-based radiocarbon dating enhanced its application and timeframe. Radiocarbon dating of peat from Aeolian deposits on the strath terraces of the Rudugaira and Gangotri glaciers, as well as lacustrine deposits in the Bhagirathi valley, ranges from 8 to 23 ka. The radiocarbon ages are perfectly correlated with OSL ages from the same sample. The radiocarbon dating based reconstruction of glacial chronologies has further enhanced our understanding of glacial dynamics and evolution of landforms during Quaternary period.