Skip to main content
U.S. flag

An official website of the United States government

High REE and Y concentrations in Co-Cu-Au ores of the Blackbird district, Idaho

January 1, 2006

Analysis of 11 samples of strata-bound Co-Cu-Au ore from the Blackbird district in Idaho shows previously unknown high concentrations of rare earth elements (REE) and Y, averaging 0.53 wt percent ???REE + Y oxides. Scanning electron microscopy indicates REE and Y residence in monazite, xenotime, and allanite that form complex intergrowths with cobaltite, suggesting coeval Co and REE + Y mineralization during the Mesoproterozoic. Occurrence of high REE and Y concentrations in the Blackbird ores, together with previously documented saline-rich fluid inclusions and Cl-rich biotite, suggest that these are not volcanogenic massive sulfide or sedimentary exhalative deposits but instead are iron oxide-copper-gold (IOCG) deposits. Other strata-bound Co deposits of Proterozoic age in the North American Cordillera and elsewhere in the world may have potential for REE and Y resources. IOCG deposits with abundant light REE should also be evaluated for possible unrecognized heavy REE and Y mineralization. ?? 2006 by Economic Geology.

Publication Year 2006
Title High REE and Y concentrations in Co-Cu-Au ores of the Blackbird district, Idaho
DOI 10.2113/gsecongeo.101.2.275
Authors J. F. Slack
Publication Type Article
Publication Subtype Journal Article
Series Title Economic Geology
Index ID 70030594
Record Source USGS Publications Warehouse