The role of CO<sub>2</sub> in the genesis of Dabie-type porphyry molybdenum deposits.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38844505.
- Also identified by DOI 10.1038/s41467-024-49275-0 and PMC identifier 11156875.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Porphyry-type molybdenum deposits, many of which are in China, supply most of the World's molybdenum. Of particular importance are the molybdenum deposits located in the Qinling-Dabie region that are responsible for more than half of China's molybdenum production. A feature that distinguishes this suite of deposits from the better-known Climax and Endako sub-types of porphyry molybdenum deposits is their formation from CO<sub>2</sub>-rich magmatic-hydrothermal fluids. The role of CO<sub>2</sub>, if any, in the transport of molybdenum by these fluids, however, is poorly understood. We conducted experiments on the partitioning of molybdenum between H<sub>2</sub>O-CO<sub>2</sub>, H<sub>2</sub>O-NaCl, and H<sub>2</sub>O-NaCl-CO<sub>2</sub> fluids and a felsic melt at 850 °C and 100 and 200 MPa. Here we show that the exsolution of separate (immiscible) brine and vapor leads to the very high brine D<sub>Mo</sub> values needed for efficient extraction of Mo from the magmas forming Dabie-type porphyry molybdenum deposits.