EGU23-12219
https://doi.org/10.5194/egusphere-egu23-12219
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Deciphering the variation of magnetic fabric intensity across the Main Central Thrust in Garhwal Himalayas

Asha Borgohain1, Pradeep Gairola1, Sandeep Bhatt1, Virendra Rana1, and Sayandeep Banerjee2
Asha Borgohain et al.
  • 1Indian Institute of Technology Roorkee, Department of Earth Sciences, Roorkee, India (asha_b@es.iitr.ac.in)
  • 2Centre of Advanced Study in Geology, Banaras Hindu University, Varanasi 221 005, India

One of the key aspects of understanding the rapid exhumation of Himalayan core, is to understand the variation of deformation intensity occurring along the major tectonic unit i.e., the Main Central Thrust (MCT). Quantification of magnetic fabrics, derived from analysis of anisotropy of magnetic susceptibility (AMS), defines the strain path in the form of an ellipsoid and provides a rich source of information on the structural evolution of rocks throughout the MCT. The approach of this study is to integrate field and AMS parameters, where field foliation from 73 planes has orientation trending NW-SE with a moderate dip of about 600 (best fit great circle) The magnetic foliation is found to be parallel to the field foliation. Variation in orientation direction of magnetic lineation implies the dominance of superposed folding in the study area. The degree of anisotropy (Pj), which quantifies the intensity of preferred orientation of magnetic minerals show values ranging from 1.1 to 1.8. The AMS study reveals that the shape parameter(T) of susceptibility ellipsoid, in most of the samples are positive representing an oblate ellipsoid. To be more precise, this study reflects the inter-relationship between field structures, superposed folding, magnetic fabric parameters to understand the exhumation of Himalayan core.

How to cite: Borgohain, A., Gairola, P., Bhatt, S., Rana, V., and Banerjee, S.: Deciphering the variation of magnetic fabric intensity across the Main Central Thrust in Garhwal Himalayas, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12219, https://doi.org/10.5194/egusphere-egu23-12219, 2023.