Main Progress and Achievements in Supplemental Regional Geological Survey of 1∶250 000 Yumenzhen Sheet
LIANG Ming-hong1, HUO Qin-zhi1, LI Hai-lin2
1. Gansu Institute of Geological Survey, Lanzhou, Gansu 730000,China; 2. Gansu Bureau of Geology and Mineral Exploration and Development, Lanzhou, Gansu 730000, China
Abstract：The regional geological survey project of 1∶250 000 Yumenzhen sheet (K47C004001) has got some progress and achievements. In this project, we have found that the Dunhuang Group was mainly composed of a series of Paleoproterozoic khondalite rocks, and a set of epimetamorphic volcanic rocks, epimetamorphic fine clastic rocks and carbonate rocks. Combining with a large number of microfossil evidence, we confirmed that the three rock units were corresponding to the Qianluzigou group of Changcheng period, the Pingtoushan and Yema formation of Jixian, respectively. By using the innovative technology of finite strain measurement, five deformation events in the Dunhuang Group were identified on the basis of a detailed analysis of the ductile shear zone in this region. Through the statistics of the sedimentary grains, seven grain coarsening events in Changma alluvial fan were identified. Combining with a large number of ESR dating data, we suggested that the sediment grain size abrupt event and uplift of the plateau had a positive connection. In addition, we also found out the spatial-temporal distribution and evolution sequence of intrusive rocks in this region, and divided these intrusions into four types: homologous, heterologous, tectonic melange, and metamorphic.
梁明宏，霍勤知，李海林. 1∶25万玉门镇幅区调修测主要进展及成果[J]. 中国地质调查, 2014, 1(2): 7-14.
LIANG Ming-hong, HUO Qin-zhi, LI Hai-lin. Main Progress and Achievements in Supplemental Regional Geological Survey of 1∶250 000 Yumenzhen Sheet. , 2014, 1(2): 7-14.
2014, Vol. 1 
