Sedimentary environment analysis of Neoproterozoic submarine fan in Jixi, southern of Anhui Province
Peng Liang1, Li Shuangying1, Huang Jialong1, Cheng Cheng1, Wu Degen2
1. School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009;
2. No.332 Geological Team, Bureau of Geology and Mineral Resources of Anhui Province, Huangshan, Anhui 245000
The study area located in Yangxi town of Jixi, Anhui Province, is mainly a set of clastic sedimentary rock of Neoproterozoic, which has a thickness of 639.7 m. The strata are mainly comprised of mudstone, argillaceous siltstone, sandstone, pebbly sandstone and conglomerate. Sedimentary structures contain horizontal bedding, graded bedding, bedding and rhythmic bedding. Tb, Tc and Td of Bouma sequences can be recognized. Probability cumulative grain-size curves have a high content of saltation population, ranging from 35%～58%. The upper segment of the profile, 254.8 m in thickness, consisting of fine argillaceous siltstone, mudstone, silty mudstone, developing horizontal bedding and graded bedding, is deposited in the lobe of outer fan. The middle segment of the profile, 192.5 m in thickness, is composed of siltstone, fine sandstone, argillaceous siltstone. Sandstone ribbon is widely distributed in the middle segment, which is considered to be deposited in channel of middle fan. The lower segment with 192.4 m thickness is a set of conglomerates interbedded with silty mudstone, and the conglomerates have a poor sorting, which was regarded to be deposited in channel of upper fan. As a whole, a set of submarine fan sedimentary sequence formed during the retrogradation.