Grain Size Characteristics and Their Paleo Environmental Significance of Xinghua 1# Core Sediments in Northern Jiangsu Basin, China
Wei Yan, Shu Qiang, Chen Ye(School of Geographical Science, Nanjing Normal University, 210097, Nanjing, China)
Grain-size characteristics of Xinghua 1# core sediments in Northern Jiangsu Basin are studied to analyze the evolutive course of deposit environment, and the sediments have a record of 3MaB.P. continuous deposit. These studies cover lithological description, mean grain-size, Md-S_0 scattered diagram, and probability accumulative curve. The analytical results of the sediments in the sect help us find out that the basic composition of sediment particles is dominated by clay, sand and silt sand, with frequent changes of the sedimentary environment. Compartmentalizing 6 deposit phases are made in terms of the meanings of deposit environment reflected by grain-size parametric characteristics. It is alternation of fluvial and lacustrine sedimentary enviroment in the depth of 350～296.1m, and lacustrine sedimentary environment in 296.1～254.1m,and fluvial sedimentary environment in 254.1～230.1m,and shallow lacustrine sedimentary enviroment in 230.1～156.2m,and lakefront sedimentary enviroment in 156.2～102.8m,and limnological sedimentary enviroment in 102.8～0m. So these explain evolutive course of deposit environment 3MaB.P. in Northern Jiangsu Basin. Furthermore, the sediments record twice immense transformation of mosoon climate in 2.26～2.16MaB.P. and 0.9MaB.P..