Geothermal development geothermal resources council. The anomolously high rate of heat flow may be due to present, or fairly recent, orogenic or magmatic activity, or to the radioactive decay of isotopes of k, th, and u where these occur at very high concentrations in crustal granites hot dry rocks. The correlative location of the model cross section in the coso range is shown as. Determination of the heat content of the fluids that will be discharged by the wells in the geothermal field 7. This is a very worthy addition and a real bargain given the material that it contains. Highly recommended for all students doing summer field camp or anyone involved in geological mapping. Austin found the location of the field, planned the project, obtained the funding and negotiated the contracts with the navy. It covers an area of about 400 km2 in lake county and has been intensively studied since the early 1970s. Geologic fundamentals of geothermal energy crc press. The project is located on the test and evaluation ranges of the naval air weapons station, china lakethe navys premier research. Coso began generating electricity in 1987 and the power is sold into the local utility grid. Located in coso volcanic field, within the china lake u. Although most basalts associated with this event are highly potassic, those at coso are not. The 6 km reflector tentatively is interpreted to be a pocket of magmatic brine or partial melt.
This deformation appears to have involved uplift of the coso range magmatic complex relative to subsidence and faulting within the owens lake graben between the sierra nevada and inyo mountains frontal faults. Carl austin, a navy geologist specializing in rock mechanics, recognized the geothermal potential of the coso area in the late 1960s. Seismicity and seismic stress in the coso range, coso. The geology of geothermal fields are quite variable from. A joint geophysical analysis of the coso geothermal field, southeastern california research pdf available june 2015 with 233 reads how we measure reads. Hauksson and unruh, 2007 and induced seismicity arising from geothermal power production kaven et al. The coso geothermal system is developed within a pliopleistocene volcanic field.
It is believed the heat source for the coso geothermal resource is a hot molten rock or magma body located at a depth of sixtoseven miles beneath the surface of the field. Magmatic evolution of the coso geothermal area, california. N2 new data from yellowstone national park and coso hot springs, inyo county, california, show anomalous concentrations of hg in soils, rocks and hot spring deposits from these thermal regions. Ratings rationale the rating action reflects cosos debt restructuring that we understand occurred on february 16, 2017. A multidisciplinary program of geothermal assessment carried out in the 1970s defined a potential resource of 650 megawatts electric with a nominal life span of 30 years. Coso geothermals possible default in july 2015 is credit negative moodys investors service 06 aug 2014. These deposits may have been related to a large low to moderatetemperature. Notes from structural geology of north america 12 9. Pdf geologic setting of the west flank, a forge site. Three main studies bear on the structure of the coso geothermal field below 5 km depth. To download the 2019 grc transactions or email citation lists, please sign in as a member in the upper righthand corner of the screen. The area is bounded by the walker lane on the northeast, the garlock fault on the south, and the sierra nevada range on the west. T1 natural concentrations of hg in the yellowstone and coso geothermal fields.
Energy and geoscience institute, university of utah. Geothermal development he coso geothermal field, located in east central california fig. Naval air weapons station near ridgecrest, california, commercial power development began in the 1980s. This deformation appears to have involved uplift of the coso range magmatic complex relative to subsidence and faulting within the owens lake graben. Having been a field geologist in the past, i have a number of field geology books on my shelf. Differentiating induced and natural seismicity using space. Geothermal energy stands out because it can be used as a baseload resource. Ascertaining that a useful geothermal production field exists 3. The original intent was to publish the work as a handbook. At least three episodes of geothermal activity have affected the area during the last 300,000 years.
The clear lake volcanic field has been active for the last 2 million years. Seismicity and seismic stress in the coso range, coso geothermal field, and indian wells valley region, southeastcentral california, geologic evolution of the mojave desert and southwestern basin and range, allen f. Geology dictates a how geothermal resources can be found, b the nature of the geothermal resource such as liquid or vapordominated an. Subsurface characterization of the coso geothermal field. By continuing to browse this site you agree to us using cookies as described in about cookies. Ratings rationale the rating action reflects coso s debt restructuring that we understand occurred on february 16, 2017. Navy has operated a network of 18 threecomponent digital borehole seismometers at coso, of them within or near the producing field, to monitor microearthquakes meqs alvarez, 1992. The feedback between stress, faulting, and fluid flow.
The main field is associated with high seismicity rates, high temperatures 640. It consists of 38 old rhyolitic lava domes and basaltic cinder cones covering a 400 sq km area. The coso volcanic field is well known as a geothermal area. Accompanying cdrom includes text of all chapters pdf files and 16 files with various maps of the southwestern basin and range province and the northern mojave desert, presented in a. The coso geothermal resource is a liquiddominated hot water source contained within the heterogeneous fractured granite rocks of the coso mountains. A joint geophysical analysis of the coso geothermal field. The reflector is most probably the sharp boundary between the northern part of the field where there is significant fluid flow and the southern part where hydrothermal fluids are absent. Feb 22, 2017 moodys investors service moodys has withdrawn coso geothermal power holdings llc coso ca rating and stable outlook following the completion of the issuers debt restructuring earlier this month. The reflector exhibits slight antiformal geometry and appears to be restricted to the northern part of the producing zone. Pdf a joint geophysical analysis of the coso geothermal. University of utah, department of geology and geophysics 5 south 1460 east room 719, salt lake city, ut 841120111 2. Natural concentrations of hg in the yellowstone and coso. This is the seventh paper in this series presenting the new technique of fluid inclusion stratigraphy. Regional tectonics of the coso geothermal area along the.
Accompanying cdrom includes text of all chapters pdf files and 16 files with various maps of the southwestern basin and range province and the northern mojave desert, presented in a variety of formats. An enhanced geothermal system at coso, californiarecent. Fluid temperatures exceeding 300oc have been measured at depths of less than 10,000 ft, and the. These wells can be up to 20,000 feet deep, tapping into a large hot fluid reservoir that has developed within the granitic basement.
The renaissance palm springs hotel room block is only available from 1422 september. It contains about 100 eruptive units and its activity can be divided into four periods. Introduction this paper presents new seismic images of the coso geothermal field in eastern california fig. The coso geothermal field which is one of the electricity generating geothermal fields in the basin and range province wilson et al. Modeling the geochemical effects of injection at coso. Then water is pumped down to it and the heat is harvested in steam or hot water. About cookies, including instructions on how to turn off cookies if you wish to do so. The coso geothermal area probably is seismically the bestmonitored producing geothermal area in the world. The coso volcanic field is located east of the sierra nevada range at the western edge of the basin and range province, california. Coso geothermal field oxidation of h2s to elemental sulfur as depicted in equation 1. Geothermal energy in the coso field owes its origin to basaltic magmatism. Initially developed in 1987, the coso geothermal field today pulls geothermal energy from about 85 wells at any given time. Coso geothermal power holdings llc credit rating moodys. Grc annual meeting fieldtrips geothermal resources council.
Travertine deposits that formed at 307 ka represent the earliest thermal activity. The east flank of the coso geothermal field is an excellent setting for testing enhanced geothermal system egs concepts see fig. Introduction a critical component in understanding the hydrothermal properties of complex geothermal reservoirs, typical of the coso geothermal field, is technology to provide images of subsurface structures, which control geothermal fluid flow. Basics of geothermal energy production and use gives an overview of what you should know about this renewable energy resource. Natural concentrations of hg in the yellowstone and. Coso, fluid geochemistry, fluid inclusions, gase ous species. A major example is the coso geothermal field in eastern california. Coso geothermal field geological society of america bulletin, novemberdecember 2005 1539 crust has thinned by more than 50% in the most highly extended part of the model. Robert comptons classic field guide to geological mapping is now available as a pdf ebook. Introduction a critical component in understanding the hydrothermal properties of complex geothermal reservoirs, typical of the coso geothermal field, is technology to provide images of subsurface. The 2019 grc transactions are now available for free download by members.
Coso geothermal system northern california geological. Coso geothermal area, two main questions have emerged. Fumaroles are present along faults bounding the rhyolitecapped horst and locally within the rhyolite field. Coso geothermal system northern california geological society. Geothermal energy plants can be started in hot dry rock simply by drilling down to it and fracturing it. This book, unlike others, examines the geology related to geothermal applications.
Crustal structure determined from ambient noise tomography. If the terminal pleistocene lake overflowed, as suggested here, then its outlet has also been raised since 12. More recently, an extensive egs reference database has been compiled vuataz and cattin, 2004. Moodys investors service moodys has withdrawn coso geothermal power holdings llc coso ca rating and stable outlook following the completion of the issuers debt restructuring earlier this month.
The normal faults divide the geothermal field into three main geologic subregions. The correlative location of the model cross section in the coso range is shown as aa. Geologic setting of the west flank, a forge site adjacent to the coso geothermal field conference paper pdf available february 2016 with 276 reads how we measure reads. The largest group of geothermal power plants in the world is located at the geysers, a geothermal field in california, united states. A broad general survey of geothermal exploration techniques is reported in combination with one specific case study.
Geologic history of the coso geothermal system michael c. The coso geothermal field is located in the central coso range, which is part of the triangleshaped area known as the southwest basin and range geographicgeologic province fig. Journal of volcanology and geothermal research volume, issues 12, 15 february 2004, pages 6175 scattering from a fault interface in the coso geothermal field. Power plants at the coso geothermal field are operated by caithness energy, llc reno, nv. Coso volcano, california canada and usa mainland facts.
Coso geothermal field 15 years of successful h s emission. In addition, fluid inclusion analysis was carried out on drill cuttings from the 1990s through 2005 to determine the geology and thermal history of the geothermal field. Areas of geothermal potential in the vicinity of the naval weapons center 7 3. Coso geothermal field coso geothermal system is a volcanic hosted system and is a mixed californiasierran and basin and range system. Scattering from a fault interface in the coso geothermal field. An enhanced geothermal system egs field experiment will be conducted to hydraulically stimulate injection well 349rd2, located on the east flank of the coso geothermal reservoir, with the objective of increasing the injection rate of this well to 750 gpm at a wellhead pressure of 100 psi or less. Fieldtrips from geothermal resources council annual meeting announced pdf june 10 please note. Fluid stratigraphy of the coso geothermal reservoir. The coso geothermal field cgf has an abundance of both natural and induced seismicity, with natural seismicity arising from tectonic and magmatic sources manley and bacon, 2000. The last full book comptons geology in the field and maleys book on field geology.
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