| Abstract: | Manifestations of a major thermal anomaly in the Geysers-Clear Lake area of northern California include the late Pliocene to Holocene Clear Lake Volcanics, The Geysers geothermal field, abundant thermal springs, and epithermal mercury and gold mineralization. The epithermal mineralization and thermal springs typically occur along high-angle faults within the broad San Andreas transform fault system that forms the western boundary of the North American plate in this area. The young volcanic rocks overlie Mesozoic marine rocks of the Great Valley sequence which have been thrust above the coeval Franciscan Complex and penecontemporaneously dropped back down along low-angle detachment faults. Geothermal power production has peaked at The Geysers and pressure declines indicate significant depletion of the fluid resource. It is proposed that recently discovered, isotopically shifted steam in the northwest Geysers area indicates the presence not of deep connate water but rather of boiled-down, boron-rich Franciscan evolved meteoric water. This water is likely to be present in limited quantities and will not provide a significant hot water resource for geothermal power production at The Geysers field or from the main Clear Lake volcanic field. -from Authors |
| Genre: | Article |
| ProdID: | 70018318 |
| Citation Author: | Donnelly-Nolan, J. M.; Burns, M. G.; Goff, F. E.; Peters, E. K.; Thompson, J. M. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 316 |
| Citation Issue: | 2 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Economic Geology |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 16 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | The Geysers-Clear Lake area, California: thermal waters, mineralization, volcanism, and geothermal potential; 1993; Article; Journal; Economic Geology; Donnelly-Nolan, J. M.; Burns, M. G.; Goff, F. E.; Peters, E. K.; Thompson, J. M. |
| Citation Start Page: | 301 |
| Citation Volume: | 88 |
| Citation Year: | 1993 |
| Type: | citation/reference |
| Text: | The Geysers-Clear Lake area, California: thermal waters, mineralization, volcanism, and geothermal potential; 1993; Article; Journal; Economic Geology; Donnelly-Nolan, J. M.; Burns, M. G.; Goff, F. E.; Peters, E. K.; Thompson, J. M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Fri, 1 Jan 1993 00:00 -0600 |
| Publisher: | |
