滇西施甸观音寺一带沙河厂组的识别

ON THE RECOGNITION OF THE SHAHECHANG FORMATION IN THE GUANYINSI AREA OF WESTERN YUNNAN

通过区域地质调查工作,笔者在滇西银川街观音寺一带原属奥陶—泥盆系中采获寒武纪芙蓉世中期的化石,确定为寒武系芙蓉统的沉积。结合区域地层对比,将观音寺一带原划为奥陶系蒲缥组、奥陶系—志留系仁和桥组、志留系栗柴坝组和泥盆系何元寨组厘定为芙蓉统沙河厂组,这一发现改变了观音寺一带的地层分布格局,提高了该地区的基础地质研究程度,对重塑该区域的地质发展起到了重要意义。

During the 1/50000 regional geological survey in recent years, the authors recognized the exist- ence of Furongian Series （Cambrian System） in the Yinchuanjie and Guanyinsi areas of western Yunnan Province. These strata were previously mapped as the Ordovician Pupiao Formation, the Ordovician--Silu- rian Renheqiao Formation, the Silurian Lichaiba Formation, and the Devonian Heyuanzhai Formation. The discovery of Furongian fossils in these strata indicate that they are of Cambrian age, and they are here de- scribed as the Shahechang Formation and are correlated with Cambrian strata in adjacent areas on the basis of biostratigraphic data. The results have important implications for regional stratigraphic correlation, ba- sin development, and tectonic history.