Journal
INTERNATIONAL GEOLOGY REVIEW
Volume 54, Issue 3, Pages 348-367Publisher
TAYLOR & FRANCIS INC
DOI: 10.1080/00206814.2010.543789
Keywords
Diancang Shan metamorphic massif; microstructures; EBSD textures; SHRIMP zircon U-Pb dating; Ailao Shan-Red River shear zone
Categories
Funding
- National Natural Science Foundation of China [40872139]
- Ministry of Education [B07011]
- State Key Laboratory of Geological Processes and Mineral Resources [GPMR200837]
- Fundamental Research Funds for the Central Universities [GPMR2009PY01]
Ask authors/readers for more resources
The Diancang Shan metamorphic massif, the northwestern extension of the Ailao Shan Massif, is a typical metamorphic complex situated along the NW-SE-trending Ailao Shan-Red River shear zone. Diancang Shan granitic and amphibolitic mylonites collected from sheared high-grade metamorphic rocks were studied using petrographic and electron-backscatter diffraction techniques. Sensitive high-resolution ion microprobe U-Pb dating of zircon grains from the granitic mylonites constrains the timing of shearing. Macro-and microstructural and textural analysis reveals intense plastic deformation of feldspar, quartz, and amphibole under amphibolite-facies conditions, all consistently document left-lateral shearing. Porphyritic monzogranitic mylonite within the shear zone possesses evidence supporting a sequential, progressive process from crystallization during magma emplacement, through submagmatic flow to solid-state plastic deformation. We suggest that the early-kinematic pluton subsequently underwent strong left-lateral strike-slip shearing. The development of complex textures of quartz, feldspar, and amphibole from the granitic and amphibolitic mylonites apparently records successive variation of conditions attending coherent, solid-state high-temperature ductile deformation during regional left-lateral shearing. All magmatic zircons from the mylonitized porphyritic monzogranite give U-Pb ages of 30.95 +/- 0.61 million years for the crystallization of the granite. This age provides the timing of onset of left-lateral shearing along the Ailao Shan-Red River shear zone in the Diancang Shan high-grade metamorphic massif.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available