- GeoRef, Copyright 2004, American Geological Institute.
The results of the Rb-Sr isotopic dating of black shale at the Sinian (Precambrian)-Cambrian boundary at the Meishucun section, Jinning County, Yunnan Province, China. The Sinian and Cambrian strata in eastern Yunnan are well developed, the Sinian-Cambrian boundary section in the vicinity of Meishucun Village in Jinning County being representative. An Rb-Sr isochron age of 579.7+ or -8.2 Ma has been obtained on black shale from the Badaowan Member of the Early Cambrian Qiongzhusi Formation, which occurs at 20 m above the Sinian-Cambrian boundary. So an inferred age of 610+ or -10 Ma is given for the Sinian (Precambrian)-Cambrian boundary.--Modified journal abstract.