华南地区二叠纪栖霞组碳酸盐岩成因研究及其地质意义

Origin of Permian Chihsian Carbonates from South China and Its Geological Implications

二叠系栖霞组是华南地区一个特殊的碳酸盐岩地层,富含有机质和燧石结核,具广泛的空间分布,但是岩相和厚度变化极小,同时发育天青石结核和海泡石。概述前人对这些沉积特殊性的研究成果及存在问题。对其特殊性的深入成因分析表明,栖霞组其他沉积特殊性均与栖霞期的缺氧沉积环境有关,而缺氧沉积环境的成因可能与栖霞期较高的生物产率有关。根据栖霞期全球古气候、古海洋背景研究的最新进展,结合栖霞组的沉积学特征,认为栖霞组特殊性的成因可能与当时较高生物产率有关,进一步研究、确定栖霞期较高生物产率的成因及其变化将具有重要的地质意义。

The Permian Chihsia Formation of South China is a unique carbonate succession, which is rich in organic matter and chert nodule, and is characterized by the great lateral persistence with little variation in lithofacies and strata thickness. Two special diagenetic minerals, nodular celestite and sepiolite, are developed in the carbonate succession. Comprehensions on the origin of the above mentioned features implied that oxygen deficient environmental condition was a critical controlling factor among these features. Based on sedimentary features of the carbonate succession, it was proposed that the Chihsian deficient environments were derived from relatively high bioproductivity. This explanation is compatible with recent advancements in the Permian paleocliamatology and paleoceanography, but further work on the origin of the high bioproductivity is still desired.