济阳坳陷沙河街组锶硫同位素特征

Characteristics of Strontium and Sulfur Isotopes in Shahejie Formation of Jiyang Depression

通过对研究区锶硫同位素特征分析,探讨济阳坳陷古近纪是否遭受过海侵作用。结果表明：沙四上亚段和沙三下亚段87Sr/86Sr值为0.7076-0.7099,属于同时期海相锶同位素范围;沙四上亚段δ34S为15‰-24‰,也属于同期海相硫同位素范围。结合前人研究成果,认为济阳坳陷沙四上亚段和沙三下亚段沉积时段曾不同程度受到海侵作用的影响。

By characteristic analysis of strontium and sulfur isotopes in the studied area, it was discussed whether the transgression has happened in Paleogene in the Jiyang depression. The results show that the content ratio of 8rSr/86Sr ranges from 0. 707 6 to 0. 709 9 in the upper fourth sub-member and the lower third sub-member of the Shahejie Formation, and the content ratio of δ^34S ranges from 15‰ to 24‰ in the upper fourth sub-member. All of these isotopic ratios are within the range of the marine isotopes. Referring to other previous research, it is concluded that the transgressions have happened in the upper fourth sub-member and the lower third sub-member of the Shahejie Formation.