Geometry and Kinematics of Masha Fault in Nesa District(Karaj-Chalus Road)

Category Tectonic & Seismotectonic
Group GSI.IR
Location 21th symposium on geosciences
Holding Date 24 May 2008

Abstract:
      Mosha fault is one of the principal faults in southern part of central Alborz Range, which has a key role in tectonic evolution of the range. It is also the main source of ancient seismic events near capital city of Tehran. Studies on geometry and kinematics of the fault in seven distinct structural sections display that the fault is a north dipping reverse fault with 60 to 80 dip angles. Kinematics of the fault in the main fault segment was determined using sigmoidal open gash and S-C structure on fault zone. They demonstrate top to the south movement of the fault. These kinematics indicators also show the semi-ductile condition for the fault zone. Unlike some references no significant left lateral movement of the fault documented in the studied segment. Though such left lateral movement were seen along minor branches of the fault.

General:
     Mosha foult is one of the principal faults in southern part of central Asborz Range, which has a key role in tectonic evolution of the range. It is also the main source of ancient seismic events near capital city of Tehran. Studies on geometry and kinematics of the fault in seven distinct structural sections display that the fault is a north dipping reverse fault with 60 to 80 dip angles. Kinematics of the foult in the main fault segment was determined using sigmoidal open gash and S-C structure on fault zone. They demonstrate top to the south movement of the fault. These kinematics indicators also show the semi-ductile condition for the fault zone. Unlike some teferences no significant left lateral movement of the fault documented in the studied segment. Though such left lateral movement were seen along minor branches of the fault.

tags: TEHRAN