Eastern Mineral and Environmental Resources Science Center
Primary Contact: Albert Hofstra, ahofstra@usgs.gov
How did the IOCG and related deposits in the St. Francois Mountains form? Specifically, what were the pressure-temperature conditions and depth of ore formation, chemical composition of ore fluids, and sources of ore fluid components that produced IOCG (e.g. Boss/Bixby) and related iron oxide and rare earth element (e.g. Pea Ridge) deposits? The initial focus will be on the Pea Ridge deposit.
The objectives of this task are to use fluid inclusion data collected from ore and gangue minerals to ascertain the presence or absense of basinal or crustal vs. magmatic or mantle fluids and their relative importance to ore formation as well as advance understanding of the P-T-X conditions and processes of mineral precipitation. Melt inclusions in coeval intrusive and extrusive igneous rocks may also be characterized. Ultimately, such data may elucidate the controls on iron oxide versus copper-gold versus rare earth element mineralization in the district and their relation to the geotectonic framework of the region.
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| Mineral Resources | Eastern / Central / Western / Alaska / National Minerals Information |
| Crustal Geophysics and Geochemistry / Spatial Data |