Current Science

Anand K. Pandey ¹, Prabha Pandey ¹, Guru Dayal Singh ², Navin Juyal ³

Affiliations
1 CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, IN
2 Geological Survey of India, Gandhinagar 382 010, IN
3 Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, IN

Abstract

The Himalayan mountain front is characterized by front parallel longitudinal valleys called Dun, that occupy the synformal troughs. The perennial glacialfed rivers Ganga and Yamuna experience first major gradient loss along the valley floor of Dehra Dun and produce characteristic landforms and deposits by the gradational processes of streams that are often controlled by climate fluctuation. In Dun valley, barring an isolated patch of ∼26 and 20-ka-old terrace, no strath terrace older than the Holocene is observed along the Ganga and Yamuna rivers. A large stretch of the Dun valley is being filled by piedmont deposits that started aggradation since >40 ka until the beginning of the Holocene and have since been undergoing incision. A similar trend is observed in upper Ganga valley, where multiple Late Quaternary aggradational terraces are observed. We analyse these landforms and associated deposits in the Dun valley to unde rstand the role of Late Quaternary-Holocene climate fluctuations and their effect on associated gradational processes.

Keywords

Climate Change, Geomorphic Landforms and Deposits, Gradational Processes.

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