Sr isotope of fossil foraminiferal assemblages in the Nihewan Group
摘要
Debate on depositional environment about foraminifera-rich strata in many Cenozoiccontinental basins in East China has existed for a long time. Research results achieved inrecent years show that it is difficult to distinguish foraminiferal assemblages in modern saltylakes from those in weakly marine environments such as supratidal zone and lagoon.However, shell geochemistry may be an outlet for this problem because of great differencein chemical and isotopic compositions between lake water and sea water. So fossils ofNonion shansiensis (Evolutononion shangiensis N. Wang), which is a sole foraminiferal speciespreserved in upper part of bed 27 and bed 28 in Xiaodukou section in the Nihewen Ba-sin, were selected for Sr isotopic measuremnts. The sequence is larger than 12 m in length