Sedimentary Carbonate-Hosted Giant Bayan Obo REE-Fe-Nb Ore Deposit of InnerMongolia, China: A Cornerstone Example for Giant Polymetallic Ore Deposits of Hydrothermal Origin

摘要

Detailed, integrative field and laboratory studies of the textures, structures,chemical characteristics, and isototopically determined ages and signatures of mineralization of the Bayan Obo deposit provided evidence for the origin and characteristics faborable for its formation and parameters necessary for defining giant polymetallic deposits of hydrothermal origin.; Bayan Obo is an epigenetic, metasomatic, hydrothermal rare early element (REE)-Fe-Nb ore deposit that is hosted in the metasedimentary H8 dolostone marble of the Middle Proterozoic Bayan Obo Group. The metasedimentary sequence was deposited on the northern continental slope of the North China craton. The mine area is about 100 km south of the suture marking Caledonian subduction of the Mongolian oceanic plate from the north beneath the North China craton.