EGU2020-4206
https://doi.org/10.5194/egusphere-egu2020-4206
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Climate controlled catchment erosion in the Himalaya during the late Quaternary

Mohd Amir1, Mohd Tarique2, Waliur Rahaman2, and Debajyoti Paul1
Mohd Amir et al.
  • 1Department of Earth Sciences, Indian Institute of Technology Kanpur, Kanpur, India (mamir@iitk.ac.in)
  • 2National Centre for Polar and Ocean Research, Vasco-da-Gama, Goa, India

The alluvial sediments deposited in the Indo-Gangetic Plains originated as a result of tectonic and climatic factors controlling the exhumation and erosion of the Hinterland Himalaya. However, erosion distribution over the Himalaya and sediment delivery to the plains, on a shorter millennial time scale, are primarily controlled by the climatic factors such as glacial cover over the Himalaya and intensity of Indian summer monsoon (ISM) precipitation. Therefore, these alluvial sediment archives record important information about the past climatic changes. Here, we report the geochemical record of 87Sr/86Sr, 143Nd/144Nd (εNd), and δ13C of sediment organic matter (δ13CSOM) in a ~45 m long drill-sediment core collected from a buried channel of the paleo-Yamuna River in the northwest Indo-Gangetic Plains, Haryana to infer variations in provenance, paleoclimate, and paleovegetation during the late Quaternary. The Sr–Nd isotopic compositions (87Sr/86Sr: 0.75144–0.79241, εNd: –15.9 to –19.7) of the core sediments suggest their derivation from isotopically distinct Higher Himalaya and Lesser Himalaya end-member sources in the catchment. Down-core variability in the isotopic compositions show increased contribution from the Higher Himalaya during marine isotope stage (MIS) 1 and late MIS 3 interglacial periods due to receding glacial cover and intense ISM. The δ13CSOM values (−21.6‰ to −27.0‰, average: −25.6‰) in the core samples imply a C3 dominant paleovegetation in the catchment. Down-core variability in the δ13CSOM exhibits significant correlation with the ISM precipitation intensity, implying an increased abundance of C4 plant in response to the ISM intensification during MIS 1, and early and late MIS 3.

How to cite: Amir, M., Tarique, M., Rahaman, W., and Paul, D.: Climate controlled catchment erosion in the Himalaya during the late Quaternary, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4206, https://doi.org/10.5194/egusphere-egu2020-4206, 2020