THE FINDINGS OF THE UPPER PERMIAN IN THE CUOQIN BASIN, TIBET

The lower Permian is widely distributed in the Cuoqin Basin. Xia Daixiang called the lower Permian the Xiala Formation in the eastern part of the Cuoqin Basin in 1979. And the lower Permian of the western part of the Qiangtang Basin was named the Yangweishan Formation by the Qing\|Zang Plateau Geological Survey Team in 1982. Both the Formations are composed mostly of crystalline limestone, bioclastic limestone, striped limestone and marl. Before 1996, the definite upper Permian has not been found in the Cuoqin Basin, central Tibet, although Guo Tieying collected a few late Permian coral fossils Huayunophyllum xiagonjianense and Waagenophyllum sp.from some limestone gravels at Xiagangjian, Gaize County in 1991. We found a late Permian fauna from 87m of the top of the Xiala Formation in Aduogabu section of Xiadongxiang, Gaize County in 1996 during we participated in the geologic survey for petroleum and natural gas in this area. The elements of this fauna are the coral Waagenophyllum indicum, Enigmalites sp., Neomultithecopora cf. catenoide, Mandulapora sp., Tibetophyllum sp.; the fusulinid Reichelina simplex, R. sp.; the foraminifera Colaniella sp., Ammodiscus semiconstrictus regularis, A. sp.; the bryozoan Stenodiscus sp.; the proifera Grossotubenella irregularia, G. sp.; the brachiopod Phircodothyris sp. etc.