| Abstract: | The Mesa Formation extends from Cananea, Mexico, southeast to the Sonora River and is the main host rock of Laramide porphyry copper deposits in the Cananea District and at the Alacran porphyry prospect to the east. The Mesa consists of two members-a lower andesite and an upper dacite. The lowest part of the dacite member is a crystal tuff about 100 m thick. This tuff is the outfall of a caldera centered near the village of Ojo de Agua, dated by 40Ar/39Ar at 65.8 Ma ?0.4. The Ojo de Agua Caldera is about 9 km in diameter and is filled by a light gray biotite dacite tuff with abundant flattened pumice fragments. The volume of the caldera is estimated to be 24 km3. |
| Genre: | USGS Numbered Series |
| ProdID: | 77086 |
| Citation Author: | Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L. |
| Citation Contributing Office: | Western Region Mineral Resources |
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| Citation Language: | ENGLISH |
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| Citation Number Of Pages: | 10 |
| Citation Online Only Flag: | Y |
| Citation Phsyical Description: | iii, 7p. |
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| Citation Series: | Scientific Investigations Report |
| Citation Series Code: | SIR |
| Citation Series Number: | 2006-5022 |
| Citation Search Results Text: | The Laramide Mesa formation and the Ojo de Agua caldera, southeast of the Cananea copper mining district, Sonora, Mexico; 2006; SIR; 2006-5022; Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L. |
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| Citation Year: | 2006 |
| Type: | citation/reference |
| Text: | The Laramide Mesa formation and the Ojo de Agua caldera, southeast of the Cananea copper mining district, Sonora, Mexico; 2006; SIR; 2006-5022; Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/sir/2006/5022/ |
| Date Other: | Mon, 24 Jul 2006 00:00 -0500 |
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