| Abstract: | 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. |
| Genre: | Article |
| ProdID: | 70030594 |
| Citation Author: | Slack, J. F. |
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| Citation End Page: | 280 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Economic Geology |
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| Citation Number Of Pages: | 6 |
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| Citation Search Results Text: | High REE and Y concentrations in Co-Cu-Au ores of the Blackbird district, Idaho; 2006; Article; Journal; Economic Geology; Slack, J. F. |
| Citation Start Page: | 275 |
| Citation Volume: | 101 |
| Citation Year: | 2006 |
| Type: | citation/reference |
| Text: | High REE and Y concentrations in Co-Cu-Au ores of the Blackbird district, Idaho; 2006; Article; Journal; Economic Geology; Slack, J. F. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.2113/gsecongeo.101.2.275 |
| Date Other: | Sun, 1 Jan 2006 00:00 -0600 |
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