Himalayan Geology, Vol. 41 (1), 2020, pp. 63-72, Printed in India

Estimation of Local Stress Directions from slipped veins near Dasu, Khyber Pakhtunkhwa (KPK), Pakistan

BASHIR AHMAD^1,2*, SOHAIL AKRAM², NISAR AHMED², SHAHID JAMIL^2,3, MUREED HUSSAIN⁴

¹Water and Power Development, Authority (WAPDA), Lahore, Pakistan

²Institute of Geology, University of the Punjab Lahore 54590, Pakistan

³Consulting Engineering Geologist, Okara, Pakistan

⁴Department of Marine Geology, Lasbela University of Agriculture, Water and Marine Sciences, Uthal, Lasbela, Pakistan

*Email (Corresponding author): ahmedseis23@gmail.com

Abstract: This article discusses the estimation of local stress directions based on sheared veins. The study was conducted as a part of the field investigations of the Dasu Hydropower project on the Indus River, Khyber Pakhtun Khawa (KPK), Pakistan. The project area is located at a distance of about 400 km in the north of Islamabad along Karakorum Highway (KKH) an important link of China - Pakistan Economic Corridor (CPEC). The discontinuity data of shears has been collected from left and right banks of the Indus River at dam axis which is aligned NW-SE across the Indus River. Particular interest was to focus on shears having intersection of quartz veins with marked displacements (varies between 8 and 200 cm). An assessment of orientation of the major principal compressional stress axis is based on the relative displacement of veins, and orientation of brittle shears. The major and intermediate principal stress axis trends N50E and N40W respectively. The estimated directions of major and intermediate principal stresses were correlated with World Stress Map (WSM) of the region, and results of  Win-Tensor Software (v. 5.0.6 :2014) are matched.

Keywords: Stress directions, Vein movement, Local stress direction, World stress map, Joints interpretation, Stress regime.