Element geochemistry characteristics of different sedimentary environments of Lengke No.1, Caidamu Basin

The data of elementary analysis of the shale from Lengke l at depth of 3,000-4,418 meter shows that the shale from different sedimentary environments has obvious different content of elements.The content of trace elements Mn、Rb、Ni、U、V、B、Co、Th and Ga is obviously higher in the limnic shale,while the content in the shale of braided stream delta and flood plain is relatively low.The content of constant elements Ca、K and Mg is relatively higher near the unconformity surface and the shale of flood plain,while the content in the limnic shale is lower and has small change,especially Ca and Mg.In the marsh shale,all the elements have the lowest content.The data of elementary analysis from Lengke l indicates that element geochemistry can be used as one of the methods to identify the sequence stratigraphic interface.