云南思茅盆地东南部上三叠统歪古村组双壳化石的新资料及其地质意义

广泛分布于云南思茅盆地的上三叠统歪古村组为一套含化石稀少的红色磨拉石沉积，1∶5万区调中在思茅盆地东南部的该组中采获了丰富的双壳类化石，共有21属52种。该双壳化石组合的发现对歪古村组沉积时期双壳动物群的面貌是一个补充。根据双壳化石群的时代属性，认为歪古村组应属卡尼—诺利期的沉积，并对图区晚三叠世沉积环境的演变作了简要分析。

New information and geological sense of bivalve fossils from the Waigucun Formation in southeast of the Simao basin,Yunnan, China

Widely distributed in Yunnan Simao basin, Upper Triassic Waigucun Formation is a red molasses sedimentary containning rare fossils. In the 1∶50000 regional geological surveying process, the authors gathered rich bivalve fossils in southeast of the Simao basin, in which total of 52 species belonging to 21 genera were identified. The discovery of bivalve fossil assemblages supplied the feature of bivalve fauna during the deposition of the Waigucun Formation. According to the stratigraphic ages and characteristics of the fossils of bivalves, the authors suggested that Waigucun Formation was developed during the Carnian-Norian. We made a brief analysis on the evolution of the sedimentary environment during the Late Triassic in the map area.