|
The rock sample thin sections from the north bank of lower course of Mengjia River in western Jinggu County, Yunnan Province, southwestern China, show there are sharply clear Planar Deformation Features (PDFs for short).
Based on analysis by synthesis of remote sensing images, strata from which the samples were sampled, and the results of universal stage measurements made at the Laboratory of Mineral Rock and Ice Physics, Department of Earth and Planet Sciences, University College London, the PDFs can be considered as causing by meteorite impact.
The impact event might take place at the Cretaceous / Tertiary boundary (65 Ma ago). The shock metamorphism caused by the impact event may reach near the highest phase of higher P silica phases, the sampling location may be near the center of meteorite-impact crater. It is the first time to discover the most typical meteorite-impact-caused PDFs in China.
This work was jointly funded by the National Basic Research Program of China (973 Program)(No. 2007CB411700), the major Knowledge Innovation Programs of the Chinese Academy of Sciences (kzcx2-yw-203-01), the national program of sustaining science and technology(2006BAB19B02), and the State Fund for Natural Science of China (No. 40676039).
|
