地球学报Issue(4)：425-433,9.DOI:10.3975/cagsb.2014.04.04
江陵凹陷古近系沙市组含膏盐岩系沉积特征研究
Sedimentary Characteristics of Gypsum-salt Rocks in Palaeogene Shashi Formation of Jiangling Depression
摘要
Abstract
Located in southern central Jianghan Basin, the Shashi Formation of Jiangling Depression is composed of two sets of gypsum-salt rocks. Based on an analysis of drilling, seismic and core data, the authors sum up lithology, electrical properties and seismic response characteristics of the gypsum-salt rock. Main lithologic changes find expression in the reduction of saline minerals and the increase of terrigenous detritus content from bottom to top;electrical character is characterized by low gamma, low density, high resistivity, zero neutron and expanding caliper;there exist high amplitude, low-frequency reflection characteristics on seismic section. In combination with the paleoclimate and ancient tectonic background of the study area, the authors made an analysis of sedimentary characteristics of gypsum-salt rocks in Shashi Formation and reached the conclusion that the distribution of gypsum-salt rocks in the depression is mainly affected such comprehensive factors as material sources, ancient landscapes and lake level changes. Based on the above study, the authors hold that the salt rock deposition model of Shashi Formation is a“non-symmetrical supply”salt-formation model, mainly formed in a shallow water evaporation sedimentary environment in the late falling period of the lake basin datum level.关键词
江陵凹陷/沙市组/膏盐岩/沉积特征/成盐模式Key words
Jiangling Depression/Shashi Formation/gypsum-salt rock/sedimentary characteristics/salt-formation model分类
天文与地球科学引用本文复制引用
沈均均,陈波,王春连,宋换新,周晓峰,周林..江陵凹陷古近系沙市组含膏盐岩系沉积特征研究[J].地球学报,2014,(4):425-433,9.基金项目
本文由国家“973”计划项目(编号:2011CB403000)和中国地质调查局计划项目(编号:1212010011808)联合资助。 （编号:2011CB403000）
