Study on paleoocean environment of Pennsylvanian coral reef area in South Guizhou Province

Pennsylvanian large-scale Fomitchevella coral reef associated with brachiopods Striatifera striata and Enteletoides shuichengensis in the Triticites Zone, South Guizhou Province. Ni, Fe, Mn, Na and Sr distribution is symmetrical across the transverse section of the above two fossil brachiopod shells, indicating that the selected samples were free of any signs of diagenesis and has preserved its original seawater signal for nearly 2.9 Ma. The paleogeographical position of Fomitchevella coral reef was in a low-latitude, of about ∼20° S close to the equatorial realm in South China during the Pennsylvanian time. The stable carbon and oxygen isotopic composition of well preserved brachiopod shell calcites showed the palaeoseawater average temperature ranged from 21.60°C to 31.51°C and seawater salinity was normal. It was the ideal environment for the development of reefs.