| Autor: |
Vidal, J., Patrier, P., Beaufort, D., Maza, S., Rivera, G., Volpi, G., Morata, D. |
| Předmět: |
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| Zdroj: |
Geothermal Energy; 6/29/2023, Vol. 11 Issue 1, p1-22, 22p |
| Abstrakt: |
This study focuses on hydrothermal alteration in the geothermal reservoir of Cerro Pabellón (Andean Cordillera, Northern Chile). It is based on CP2A and CP5A production wells drilled above a local normal fault and presenting unlike hydraulic properties. Cuttings from 300 to 1555 m depth were sampled and analyzed using X-ray diffraction (XRD) to observe distribution of hydrothermal minerals and crystal chemistry variations of clays (fraction < 5 μm). Then, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDX) allowed to perform microanalysis of hydrothermal minerals. These results highlight a mineral assemblage that was not observed before, composed of adularia + Ba-rich feldspar + feathery quartz + chalcedony + calcium arsenates + illite. They are characteristics of high-temperature hydrothermal alteration in epithermal settings and are restricted to shallow permeable fracture zones of the active part of the reservoir. Another fracture-controlled event related to a typical illitization is observed in all permeable fracture and fault zones of the geothermal system. This multi-event alteration seems strongly controlled by the western graben fault and the associated interconnected fracture network. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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