对李官桥盆地上寺组时代的商榷

DISCUSSION ON THE AGE OF THE SHANGSI FORMATION IN THE LIGUANQIAO BASIN

上寺组与核桃园组为整合关系。它不是核桃园组的横向相变产物,而是核桃园组的上覆地层,具有一定的厚度,独特的岩性、明确的接触关系,是盆地回返收缩阶段的沉积。按照优先率,上寺组一名应当保留,继续使用。根据核桃园组上段所产的化石属于晚始新世,作者认为将上寺组划为渐新统较为合适。

There is a conformitive relation between the Shangsi and the Hctao formations. The Shangsi Formation is an overlying sequence with a certain thickness and distinct litho-characteristics, deposited during the basin shrinking rather than a product of lateral facies change within the Hetao Formation. According to priority, the term of the Shangsi Formation should be reserved. Since the fossils produced in the upper section of the Hetao Formation attributed to the age of late Eocene, the authors of this paper think it suitabe to define the age of the Shangsi Formation as Oligoeene.