构造与气候对江陵凹陷古近系蒸发盐沉积的耦合作用

江陵凹陷古近系厚层蒸发盐对区域构造和气候变化的响应机制仍然不明确。本文基于获取的江陵凹陷深钻SKD1岩芯和已有的研究资料,探讨了江陵凹陷古近系蒸发盐的矿物特征以及成盐环境,重建了蒸发盐的时空分布演化。研究结果表明,沙市组时期构造活动强烈,较快的沉降速率以及极端暖旱的气候使蒸发盐首先在凹陷北部沉积;新沟咀组下段沉积时,构造活动减弱,季节性干旱气候以及沉降中心向西南方向迁移等诸多因素共同导致膏盐岩在凹陷南部沉积,进一步指示在南部次级洼陷中找钾的前景。

Control of tectonocs and climate coupling on the Paleogene evaporites deposition in the Jiangling depression

Response mechnism of Paleogene thick evaporite in Jiangling depression to regional tectonics and climate change is still obsure. Based on core of the deep drill hole SKD1 operated in the depression and study results avillable this paper deals with mineral characteristics and salt rock-forming environment and spatial distribution of the evaporite. Results show that during deposition of Shashi Formation rapid subsidence rate took place due to strong tectonic movement which, together with extreme warm and dry climate led to the deposition of evaporites in the northern part of the depression. During deposition of Xingouzui Formation structural movement weakened and subsidence center moved to southwest which together with seasonal dry climate and other factors led to the deposition the south depression. The sub-basins of the south depression should be potential for further potasium propecting.