Iron-rich condition maintained throughout the mid-Proterozoic ocean: new evidence from the North China Craton

Hanqing Zhao1, Shihong Zhang1, Xiaoying Shi2, Chuanheng Zhang2, Yongjian Huang3 and Haiyan Li1, (1)China University of Geosciences (Beijing), State Key Laboratory of Biogeology and Environmental Geology, Beijing, China, (2)State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China, (3)China University of Geosciences, Beijing, China