盐湖盆地层序地层特征

CHARACTERISTICS OF SEQUENCE STRATIGRAPHY IN THE SALINE LAKE BASIN

黄春菊 陈开远 杨香华

Huang Chunju Chen Kaiyuan Yang Xianghua

盐湖盆地与碳酸岩盐的层序地层是有区别的。因此,须从气候、构造和盐类物质来源等方面分析岩盐沉积,利用岩盐沉积物中的地球化学特征揭示湖平面的变化并划分岩盐层序。潜江凹陷潜江组的碳、氧同位素在水进体系域中较轻,而在高位和低位体系域中较重;硼含量亦有类似的变化规律,低位域和高位域末期的硼含量一般较高,而在水进体系域中则变小。综合分析潜江凹陷潜江组不同物源及古地形等因素,可将潜江组划分为 3大体系域和 7个层序。

There are some distinctions between sequence stratigraphy of carbonate rock and sequence stratigraphy of the saline lake basin.Therefore,the analysis of carbonate rock sediment must start from the analysis of climate,structure and sources of saline material etc.and use geochemical characteristics of the saline sediments to reveal changes of the lake surface so as to divide the saline sequence.Isotope of carbon and oxygen in the ingression of water system tracts in Qianjiang Formation of Qianjiang depression is lighter than those in the highstand and lowstand system tracts.Boron content has a similar change regularity,boron content in the late period of highstand and lowstand system tracts is normally higher while in the ingression of water system tracts it's gradually becoming lower.Qianjiang Formation of the Qianjiang depression could be divided into 3 major system tracts and 7 sequence stratigraphies on the basis of combined analysis of its different sediment sources and comprehensive factors of its palaeo-topography.

10.11743/ogg20020206