Structure and geochronological constraints on the ductile deformation observed along the Gaoligong Shan and Chong Shan Shear Zones, Yunnan (China)

The mechanism by which the Cenozoic post-collisional northward motion of India relative to Eurasia and South China was accommodated along its eastern boundary is still a poorly understood aspect of the tectonic evolution of SE Asia. This thesis focuses on a critically important area within the India-Eurasia collision zone, a region known as the Three Rivers area, and presents the first structural and geochronological data from several transects across two poorly documented linear metamorphic belts located in between the Sagaing fault and the Ailao Shan Shear Zone: the Gaoligong Shan Shear Zone (GSSZ) and the Chong Shan Shear Zone (CSSZ) in Yunnan, China. The presently inactive GSSZ is an important dextral Cenozoic (and possibly latest Mesozoic) ductile shear zone and appears to be the only right-lateral shear zone with the appropriate orientation to accommodate major pre- ca. 11 Ma northward movement of India relative to Eurasia. The previously unknown CSSZ is a long (>300 km) and wide (10- 20 km) metamorphic belt containing an assemblage low- to high-grade rocks from possibly several tectonic units which contain a prominent sub-vertical foliation and a sub-horizontal stretching lineation. Preliminary U/Pb results indicate that the ductile dextral shearing terminated by -18 Ma. Our regional map compilations indicate that the GSSZ and its proposed conjugate, the ASSZ, likely terminate within the Bangong Co-Nujiang suture zone.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Akciz, Sinan Osman, 1974-

Advisor dc:contributor.advisor

• B. Clark Burchfiel.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/30289

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/30289