Abstract:

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.

Key words: saline lake basin, saline lake sequence, geochemistry, characteristic, saline lake surface, Qianjiang depression