| The mountain of Yunkai is the most important metallogenic belt of metal and nonmetal in the south of China, and it is also a important window of the research of geotectonics. Each strata of different age is produced in this area. Regional metamorphic rock, chorismite which are produced in Caledonian or former Caledonian , faulted metamorphic rock which is produced from Hercynian to Indosinian and magmatite which is produced in every age are distributed widely in the research area. But the various kinds of gneissoid granitics is conspicuous especially. The tectonic style of mountain of Yunkai (extensional tectonics, thrusting, ductile shear zone and gravitational slump structure) are abundant and form a complicated strain figure which shows the character of multi-stage and multi- gradation.At present, it is no consistent view about the formation of dynamics mechanism and the setting of geotectonics. Although the measure which defines the character of geotectonics is very high, the rock fabric and microstructure are important basic work in the research of tectonic geology. It reveals a lot of macro-tectonic strain regularities, strain condition, mode of motion and dynamic analysis by micro- directional regularities of tectonite fabric. Fabric analysis studys vectorial quality of natural rock and unit in space by statistical method and illustrates or probes the produced condition and metastatic history during tectonic movement. Combining structural feature of tectonic strain and the existed research data, this article discuss and analyze the kinetic mechanism of tectonic strain and tectonic setting by measuring and analyzing mylonite fabric in this area. The research shows that the antitropic advection and sheared sliding movement happened from the later Yanshanian to Himalayan. Oriented arrange of quartzous crystal axis is the result of basal glide, cylindrical glide and other mechanism. |
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