ABSTRACT
FINITE STRAIN AND KINEMATIC VORTICITY ANALYSIS OF THE ROCKS AS A TOOL TO LOCATE THE THRUSTS FAULTS IN THE HIMALAYAS: A CASE STUDY FROM THE BIRENDRANAGAR-TALPOKHARI AREA OF KARNALI PROVINCE OF NEPAL
Journal: Pakistan Journal of Geology (PJG)
Author:Ankit Kandel, Kabi Raj Paudyal
This is an open access journal distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
DOI: 10.26480/pjg.02.2023.56.72
The Birendranagar-Talpokhari area lies in Surkhet and Dailekh districts of the Karnali Province, Nepal. Geologically, the study area represents parts of the Lesser Himalaya and Sub-Himalaya. The Sub-Himalaya consists of rocks of the Lower Siwalik. The Lesser Himalaya consists of three tectonic units: the Dailekh Group, the Lakharpata Group, and the Surkhet Group. The Dailekh Group is the allochthonous rock unit consisting of sequences of metamorphosed rocks whereas the Lakharpata Group consists of series of carbonate rocks. The Surkhet Group is the para-autochthonous unit consisting of sequences of low-grade metamorphic rocks. The strain ellipsoid of the quartz grains shows the rocks of the Surkhet Group and Dailekh Group bear a differential pattern of deformation. All the samples from the Surkhet Group rocks show the (Ri>Rs) condition whereas the Dailekh Group rocks show the (Rs> Ri) condition. The kinematic vorticity numbers with higher values (sample J19, L5, and M20) are located near the thrust whereas the lower value (sample J19) lies at some distance from the thrust. The simple shear-dominated area is more affected by the shearing effect so that the long axis of the quartz grains gets affected and subjected to rotation during shearing. This result supports the presence of the regional thrusts; (Timile Thrust and Nigalpani Thrust).
| Pages | 56-72 |
| Year | 2023 |
| Issue | 2 |
| Volume | 7 |
