Controlling of the Late Palaeozoic glaciation on reef evolution: A case study of a late Kasimovian coral reef in southern Guizhou, South China

Abstract

A late Kasimovian (Pennsylvanian) coral reef is reported in the Yanbanzhai (YBZ) area, southern Guizhou Province, South China. The YBZ coral reef, with a thickness of approximately 5.5 m and a lateral exposure of nearly 50 m, is primarily composed of the colonial rugose coral Fomichevella. The fusulinids collected from the reef indicates a late Kasimovian age. Five microfacies types have been identified, including coated bioclastic grainstone, coral (Fomichevella) framestone, bioclastic wackestone, bioclastic grainstone, and peloidal grainstone. The vertical evolution of the microfacies in the YBZ coral reef indicates major sedimentary environmental changes associated with relative sea-level changes. The growth of the reef-builder Fomichevella was controlled by the transgression and regression. Deep water promoted the upward expansion of Fomichevella, while shallow water inhibited its growth. Published records of atmospheric pCO 2 estimation and sea-surface temperatures, combined with geochemical proxies, confirm a warm climatic period during the late Kasimovian. This is an interglacial period conducive to the growth of the coral reef. Sea-level and climate changes associated with the Late Palaeozoic ice age (LPIA) are interpreted as significant controls of the development of the YBZ coral reef. This research of the YBZ coral reef in South China provides practical palaeobiological evidence for global sea-level rising during the late Kasimovian period caused by the highlatitude Gondwana delaciation.