| Abstract: | Geological and geochemical studies indicate that a high-temperature geothermal system underlies the Alid volcanic center in the northern Danakil depression of Eritrea. Alid is a very late-Pleistocene structural dome formed by shallow intrusion of rhyolitic magma, some of which vented as lavas and pyroclastic flows. Fumaroles and boiling pools distributed widely over an area of ~10 km2 on the northern half of Alid suggest that an active hydrothermal system underlies much of that part of the mountain. Geothermometers indicate that the fumarolic gases are derived from a geothermal system with temperatures >225??C. The isotopic composition of condensed fumarolic steam is consistent with these temperatures and implies that the source water is derived primarily from either lowland meteoric waters or fossil Red Sea water, or both. Some gases vented from the system (CO2, H2S and He) are largely magmatic in origin. Permeability beneath the volcanic center may be high, given the amount of intrusion-related deformation and the active normal faulting within the Danakil depression.Geological and geochemical studies indicate that a high-temperature geothermal system underlies the Alid volcanic center in the northern Danakil depression of Eritrea. Alid is a very late-Pleistocene structural dome formed by shallow intrusion of rhyolitic magma, some of which vented as lavas and pyroclastic flows. Fumaroles and boiling pools distributed widely over an area of approx. 10 km2 on the northern half of Alid suggest that an active hydrothermal system underlies much of that part of the mountain. Geothermometers indicate that the fumarolic gases are derived from a geothermal system with temperatures >225??C. The isotopic composition of condensed fumarolic steam is consistent with these temperatures and implies that the source water is derived primarily from either lowland meteoric waters or fossil Red Sea water, or both. Some gases vented from the system (CO2, H2S and He) are largely magmatic in origin. Permeability beneath the volcanic center may be high, given the amount of intrusion-related deformation and the active normal faulting within the Danakil depression. |
| Genre: | Article |
| ProdID: | 70021743 |
| Citation Author: | Lowenstern, J. B.; Janik, C. J.; Fournier, R. O.; Tesfai, T.; Duffield, W. A.; Clynne, M. A.; Smith, J. G.; Woldegiorgis, L.; Weldemariam, K.; Kahsai, G. |
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| Citation End Page: | 187 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Geothermics |
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| Citation Number Of Pages: | 27 |
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| Citation Publisher: | Elsevier Science Ltd |
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| Citation Search Results Text: | A geochemical reconnaissance of the Alid volcanic center and geothermal system, Danakil depression, Eritrea; 1999; Article; Journal; Geothermics; Lowenstern, J. B.; Janik, C. J.; Fournier, R. O.; Tesfai, T.; Duffield, W. A.; Clynne, M. A.; Smith, J. G.; Woldegiorgis, L.; Weldemariam, K.; Kahsai, G. |
| Citation Start Page: | 161 |
| Citation Volume: | 28 |
| Citation Year: | 1999 |
| Type: | citation/reference |
| Text: | A geochemical reconnaissance of the Alid volcanic center and geothermal system, Danakil depression, Eritrea; 1999; Article; Journal; Geothermics; Lowenstern, J. B.; Janik, C. J.; Fournier, R. O.; Tesfai, T.; Duffield, W. A.; Clynne, M. A.; Smith, J. G.; Woldegiorgis, L.; Weldemariam, K.; Kahsai, G. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/S0375-6505(99)00002-4 |
| Date Other: | Fri, 1 Jan 1999 00:00 -0600 |
| Publisher: | Elsevier Science Ltd |
