Thenmala fault system, Southern India: Implication to neotectonics

The Achankovil shear system is one of the major crustal scale structures in Peninsular India. This NW-SE trending shear zone stretches across the Western Ghats for a strike length of 120 km. A number of parallel lineaments demarcate this 15-20 km wide shear zone. Many studies were carried out to und...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the Geological Society of India 2015-10, Vol.86 (4), p.391-398
Main Authors: Praseeda, E., John, Biju, Srinivasan, C., Singh, Yogendra, Divyalakshmi, K. S., Samui, Pijush
Format: Article
Language:English
Subjects:
Brittleness
Continental dynamics
Earth and Environmental Science
Earth Sciences
Fault lines
Faults
Geology
Hydrogeology
India
Mountains
Neotectonics
Plate tectonics
Rock deformation
Satellite imagery
Shear
Shear zone
Signatures
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Achankovil shear system is one of the major crustal scale structures in Peninsular India. This NW-SE trending shear zone stretches across the Western Ghats for a strike length of 120 km. A number of parallel lineaments demarcate this 15-20 km wide shear zone. Many studies were carried out to understand the origin and delineation of this structure. Low level seismicity reported in this region, however, does not suggest any relation with this shear zone and thus no significant study was carried out to understand its neotectonic behavior. However, there are a couple of faults identified in the southern end of this shear system viz., Thenmala and Thenmala south faults. Even though these faults were demarcated in hilly terrain of Western Ghats, its expression into the plain area east of the mountain terrain were not identified during the earlier studies. The present study however, delineated the signatures of these faults further in the southeast from satellite images. The traces of these faults are observed as multiple slip planes with varying deformation pattern. A group of N-S trending lineaments are also observed in hill ranges. Similarly, N-S trending long persistent vertical joints are observed in the plain area are free from displacement. The traces of NW-SE trending brittle faults observed in these areas crosscut all the joints including the N-S trending vertical ones. These observations suggest that the geomorphic signature associated with Thenmala lineaments may represent the youngest deformation (brittle) of the region.
ISSN:0016-7622
0974-6889
DOI:10.1007/s12594-015-0327-z