Integrated mineral magnetic and lithologic studies

Authors: S J Sangode Suman Rawat D C Meshram N R Phadtare N Suresh

Publish Date: 2013/08/16

Volume: 82, Issue: 2, Pages: 107-120

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Abstract

We present here lithofacies and mineral magnetic results from a ∼50 m thick composite record of fluvial lacustrine and aeolian facies within the Leh valley basin of Indus River in Ladakh Himalaya Mineral magnetic studies decipher interplay of two contrasting sediment sources viz the unimodal ferrimagnetic source derived from Ladakh batholithic glacial domain and mixed ferrito antiferromagnetic source derived from Indus sedimentary sequence The lithofacies variability expresses dynamic changes in the depositional regimes controlled by base level fluctuations that are governed by the interaction of basin fill conditions and the response to Late Quaternary climatic perturbations A three stage evolution of the Leh valley basin is proposed after comparison to other characteristic lithofacies changes within the valley as I the basin underfill conditions marked by fluvial and fluviolacustrine phase till ∼24m ∼64 Ka OSL age above modern base level followed by II predominantly varved glaciolacustrine basin overfill phase till 38m ∼28 Ka gradually passing into an aeolian phase and III basin incision that began at the earliest Holocene warming Advancement and retreat of glaciers from the transverse valleys attributed to climatic oscillations appears to have greatly controlled the basinfill conditions in the Leh valley The present approach demonstrates its larger scope in recording the Late Quaternary response of individual valley basins to delineate local and regional attributes of climate change in the Himalayan and Karakoram region

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