Significance of a δ¹³C anomaly near the Devonian/Carboniferous boundary at the Muhua section, South China

Abstract

The Muhua section of Guizhou Province, South China is one of three candidates for the Devonian/Carboniferous international boundary stratotype¹. Although palaeontological and stratigraphical data have been published^2,3, no stable isotope study has previously been made. Detailed δ¹³C and δ¹⁸O analyses from the Muhua section reveal a significant short-term δ¹³C negative anomaly of 8–9‰ at the base of the Siphonodella crenulata conodont zone. This is the first δ¹³C negative anomaly found near the Devonian/Carboniferous boundary, and is similar to δ¹³C anomalies reported from the Permian/Triassic, Cretaceous/Tertiary, and Precambrian/Cambrian boundaries^4,5. We suggest, therefore, that the δ¹³C anomaly at Muhua section provides evidence for major rapid changes in ocean–atmospheric chemistry, and may reflect an important event in geological history.