Marine Mo biogeochemistry in the context of dynamically euxinic mid-depth waters: A case study of the lower Cambrian Niutitang shales, South China

Cheng Meng Li Chao Zhou Lian Algeo Thomas J. Zhang Feifei Romaniello Stephen Jin Cheng-Sheng Lei Li-Dan Feng Lianjun Jiang Shao-Yong · 2016

阅读量：156

早寒武世

期刊名称：

Geochimica et Cosmochimica Acta 2016 年 183 卷

发表日期：

2016.06.15

摘要：

Molybdenum (Mo) concentrations and Mo isotopes have been widely used as proxies for local and global redox conditions in early oceans (>520 Ma) that were stratified and characterized by dynamically euxinic mid-depth waters. However, the nature of the Mo cycle and accompanying isotopic fractionations in such oceans remain poorly known. To fill this gap, we conducted an integrated study of Mo isotopes and redox-sensitive trace element (RSTE) abundances in the Lower Cambrian Niutitang Formation at Yangjiaping, South China. This section accumulated on the northern shelf margin of the Nanhua Basin, a failed intracontinental rift basin with a good connection to the open ocean during the early Cambrian. The Niutitang Formation contains a ~18-m-thick lower black shale member, and a ~56-m-thick upper gray silty shale member. The lower member (LM) is moderately to strongly enriched in Mo, U and V, and heterogeneous in Mo isotopic composition (??