A Study of Mylonites from parts of the Salem-Attur Shear Zone (Tamil Nadu) and its Tectonic Implications
DSpace at IIT Bombay
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Title |
A Study of Mylonites from parts of the Salem-Attur Shear Zone (Tamil Nadu) and its Tectonic Implications
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Creator |
BISWAL, TK
THIRUKUMARAN, V RATRE, K BANDYAPADHAYA, K SUNDARALINGAM, K MONDAL, AK |
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Subject |
south-india
stretching lineations karnataka shield moyar mylonites pseudotachylites low angle thrust salem-attur shear zone |
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Description |
The E-W running Salem-Attur shear zone demarcates the tectonic boundary between Archaean Dharwar Craton in the north and Proterozoic Southern granulite terrane in the south. This study reveals that the shear zone is a low angle thrust. The thrust zone is around 10 m thick and it merges with the main shear zone along the strike. The thrust is developed on charnockite near Odyarpatti, which is retrograded into schists. Further, it is marked by gently dipping mylonitic foliation and subhorizontal lineation. The S-C fabric, mantled porphyroclasts and intragranular faults indicate northeasterly slip along the thrust. Recumbent shear folds SF 1 are developed within the thrust zone. The thrust has been folded by late stage F 2 fold which has brought variation in the orientation of the mylonitic foliation from subhorizontal to vertical attitude; the mylonitic lineations have been rotated to subvertical orientation also. Additionally, the F 2 crenulations and shear cleavages and intersection lineations are superimposed on the mylonitic fabric. Thrusting along the Salem-Attur shear zone is probably the cause for upliftment of the charnockites to the upper crust. Post-upliftment stage has witnessed brittle deformation in the form of development of shear fractures in NNE-SSW and E-W directions. Pseudotachylites are emplaced along these fractures.
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Publisher |
SPRINGER INDIA
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Date |
2011-08-30T05:38:45Z
2011-12-26T12:58:47Z 2011-12-27T05:49:19Z 2011-08-30T05:38:45Z 2011-12-26T12:58:47Z 2011-12-27T05:49:19Z 2010 |
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Type |
Article
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Identifier |
JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA, 75(1), 128-136
0016-7622 http://dspace.library.iitb.ac.in/xmlui/handle/10054/12209 http://hdl.handle.net/10054/12209 |
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Language |
en
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