Strontium isotopic curve of the Carboniferous in Huishui, Guizhou, and chronostratigraphic correlation

Abstract：The fundamental principle of Sr isotopic stratigraphy is introduced briefly in the paper. An evolutionary curve of the Sr isotopic composition of the Carboniferous has been constructed based on 19 unaltered carbonate samples collected from the Hiushui section, Guizhou. It was correlated with a contemporaneous Sr isotope curve of North America constructed by R.E. Denison. The very close similarity between the two curves supports the globally consistent evolutionary feature of the Sr isotopic composition of ancient seawater during the geologic history. So the curve is a reliable tool for the global chronostratigraphic correlation. This paper discusses the global sea-level changes during the Carboniferous and the chronostratigraphic division and correlation of the Huishui Carboniferous section. The authors suggest that the Lower-Upper Carboniferous boundary is broadly located near the base of the Bazuo Formation and that the Carboniferous-Permian boundary lies inside the Maping Formation.