区内晚三叠世地层分布范围属西南三省(1974)统一地层区划的义敦—中甸分区(图 1),金沙江断裂以东,甘孜—理塘断裂以西广大地区。关于这个地区的三叠系,部分过去一直视作古生界,即所谓“德格群”。1967年地质部地科院川西科研队曾在德格县打马洞一带采得上三叠统的六射 The distribution of Late Triassic strata in the area belongs to the Yidun-Zhongdian subregion (Figure 1) of the unified stratigraphic division of the three southwestern provinces (1974), to the east of the Jinsha River fault, and to the vast area west of the Garze-Litang Fault. About the Triassic in this area, some of them used to be regarded as the Paleozoic, the so-called “Dege group ”. 1967 Geosciences Institute of Western Sichuan Geological Research team had Dege County in the vicinity of Ma Ma Dong mining on the Triassic six shot