Origin of siderite mineralization in western Guizhou, SW China: Constrains from REEs, C, O, Sr and S isotopes

Numerous siderite deposits in western Guizhou of SW China are mainly hosted in the Middle Devonian dolostones. The larger Caiyuanzi (CYZ) and Xiongxiongjia (XXJ) deposits have an ore reserve in excess of 300Mt with an average ore grade of ~35% total iron. There are banded and massive siderite ores and sulfide–siderite ores. The major ore mineral is magnesian siderite and gangue minerals are ankerite, dolomite, kaolinite, quartz and carbon. There are also metallic minerals including pyrite, chalcopyrite, and minor galena, tetrahedrite and enargite.