Sedimentary characteristics and geological significance of turbidites in the Lower Cambrian Qingxudong Formation at Huayuan county,northwestern Hunan
Kuang Wenlong1, Yang Shaoxiang2, Yu Peiran2, Lao Ketong2
1. School of Civil Engineering, Hunan Science and Technology University, Xiangtan, Hunan 411201; 2. No.405 Team, Bureau of Mineral Resources and Geological Exploration of Hunan Province, Jishou, Hunan 416007
This paper described main geological characteristics and typical sedimentary successions of the Lower Cambrian Qingxudong Formation at Huayuan county in northwestern Hunan province. Its erosion structure in the base was clarity,the thickness varied obviously from section to section,and grain size of clastic sediments became finer in an upword order,accompanied with occurring of deformed lamination, parallel lamination and corrugated lamination. All of these sedimentary structures indicated the turbidites deposited in an offshore environment. Based on development of Bouma sequence, five profile textures of the turbidites were concluded. The glacial ablation resulted in sea level rising, so the seawater became deeper during depositional period of the Qingxudong Formation. The turbidity current, widely distributed in northwesten Hunan and northeastern Guizhou areas, was controlled by the NEE-striking faults, and in Huayuan the current controlled by the Baojing-Huayuan fracture. The activity of the NEE-striking faults in Early Cambrian might be related to splitting of the Rodinia supercontinent, which occurred in Neoproterozoic and continued to Early Paleozoic.
Kuang Wenlong,Yang Shaoxiang,Yu Peiran et al. Sedimentary characteristics and geological significance of turbidites in the Lower Cambrian Qingxudong Formation at Huayuan county,northwestern Hunan[J]. Chinese Journal of Geology, 2008, (2): 347-358.