中文摘要：

全球膏盐岩盖层虽然所占比例较小，但封盖了大多数已发现油气储量，并且是许多大型、特大型油气田的主要盖层，对油气聚集与保存具有重要意义。中一下三叠统膏盐岩盖层与四川盆地天然气分布的密切关系也表明，膏盐岩分布特征研究是认识、评价中国南方天然气保存条件不可忽视的重要因素之一。膏盐岩主要形成于盆地发展演化的中、后期。在中国南方，膏盐岩盖层主要发育于中-下寒武统、石炭系、中-下三叠统及白垩系——古近系，但分布不均，其封盖作用的重要性差异很大。受沉积、构造环境及后期破坏作用的影响，中-下寒武统膏盐岩主要分布在四川盆地东、南部及黔西北地区；石炭系膏盐岩盖层主要分布在湘中区；白垩系——古近系膏盐岩盖层主要发育于江汉盆地。中-下三叠统膏盐岩厚度最大、分布最广，对区内天然气的封盖作用最为重要，对四川盆地、黔北区、楚雄盆地及中、下扬子部分她区的天然气都起到重萼的封蔫作用。

英文摘要：

Although accounting for a small proportion of the cap rocks all over the world, the saline deposit is of vital importance for accumulation and preservation of hydrocarbons, for it serves as seal to most of the discovered hydrocarbon reserves and is also the major cap rock in many huge and giant oil and gas fields. The close relationship between the Middle - Lower Triassic saline deposit cap rock and the distribution of natural gas in Sichuan basin suggests that distribution of saline deposit is crucial to the understanding and evaluation of the gas preserve conditions in southern China. Saline deposit forms mostly during the middle and late stages of basin development. In southern China, saline deposit cap rock are mainly developed in Middle -Lower Cambrian, Carboniferous, Middle - Lower Triassic, and Cretaceous-Paleogene, but they are unevenly distributed and have different sealing importance. Under the influence of deposition, tectonic settings, and late destruction, the salinedeposit rock of Middle - Lower Cambrian mainly distribute in the eastern and southern parts of Sichuan basin and the northwestern part of Guizhou province; the Carboniferous saline deposit mainly distributed in the central of Hunan province, and the Cretaceous-Paleogene saline deposit mainly occurs in Jianghan basin. The Middle - Lower Triassic Saline-deposit, with the widest distribution and the biggest thickness, plays an important role in the sealing of natural gas in Sichuan basin, northern Guizhou Province, Chuxiong basin, and parts of the Middie-Lower Yangtze.