Transport of Geothermal Fluids along Dikes and Fault Zones
Field observations of active and fossil natural geothermal fields indicate that geothermal fluids are primarily transported along dikes and fault zones. Fluid transport along dikes (commonly through fractures at their margins) is controlled by the cubic law where the volumetric flow rate depends on...
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ftdoajarticles:oai:doaj.org/article:4e1ab7476386457ca98f30404cb41e87 2023-05-15T16:51:19+02:00 Transport of Geothermal Fluids along Dikes and Fault Zones Agust Gudmundsson 2022-09-01T00:00:00Z https://doi.org/10.3390/en15197106 https://doaj.org/article/4e1ab7476386457ca98f30404cb41e87 EN eng MDPI AG https://www.mdpi.com/1996-1073/15/19/7106 https://doaj.org/toc/1996-1073 doi:10.3390/en15197106 1996-1073 https://doaj.org/article/4e1ab7476386457ca98f30404cb41e87 Energies, Vol 15, Iss 7106, p 7106 (2022) geothermal systems permeability fault damage zone fault core intrusions Darcy’s law Technology T article 2022 ftdoajarticles https://doi.org/10.3390/en15197106 2022-12-30T19:46:35Z Field observations of active and fossil natural geothermal fields indicate that geothermal fluids are primarily transported along dikes and fault zones. Fluid transport along dikes (commonly through fractures at their margins) is controlled by the cubic law where the volumetric flow rate depends on the aperture of the fracture in the 3rd power. Dikes (and inclined sheets) also act as heat sources for geothermal fields. In high-temperature fields in volcanoes in Iceland dikes and inclined sheets constitute 80–100% of the rock at crustal depths of 1.5–2 km. Holocene feeder-dikes are known to have increased the activity of associated geothermal fields. Fault zones transport geothermal fluids along their two main hydromechanical units, the core and the damage zone. The core is comparatively thin and primarily composed of breccia, gouge, and clay and related low-permeability porous materials. By contrast, the fault damage zone is characterised by fractures whose frequency is normally highest at the contact between the core and the damage zone. Fluid transport in the damage zone, and in the core following fault slip, is controlled by the cubic law. During non-slip periods fluid transport in the core is primarily controlled by Darcy’s law. Secondary mineralisation (forming mineral veins and amygdales) tends to reduce the fault-zone permeability. Repeated earthquake activity is thus needed to maintain the permeability of fault zones in active natural geothermal fields. Article in Journal/Newspaper Iceland Directory of Open Access Journals: DOAJ Articles Energies 15 19 7106 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
geothermal systems permeability fault damage zone fault core intrusions Darcy’s law Technology T |
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geothermal systems permeability fault damage zone fault core intrusions Darcy’s law Technology T Agust Gudmundsson Transport of Geothermal Fluids along Dikes and Fault Zones |
topic_facet |
geothermal systems permeability fault damage zone fault core intrusions Darcy’s law Technology T |
description |
Field observations of active and fossil natural geothermal fields indicate that geothermal fluids are primarily transported along dikes and fault zones. Fluid transport along dikes (commonly through fractures at their margins) is controlled by the cubic law where the volumetric flow rate depends on the aperture of the fracture in the 3rd power. Dikes (and inclined sheets) also act as heat sources for geothermal fields. In high-temperature fields in volcanoes in Iceland dikes and inclined sheets constitute 80–100% of the rock at crustal depths of 1.5–2 km. Holocene feeder-dikes are known to have increased the activity of associated geothermal fields. Fault zones transport geothermal fluids along their two main hydromechanical units, the core and the damage zone. The core is comparatively thin and primarily composed of breccia, gouge, and clay and related low-permeability porous materials. By contrast, the fault damage zone is characterised by fractures whose frequency is normally highest at the contact between the core and the damage zone. Fluid transport in the damage zone, and in the core following fault slip, is controlled by the cubic law. During non-slip periods fluid transport in the core is primarily controlled by Darcy’s law. Secondary mineralisation (forming mineral veins and amygdales) tends to reduce the fault-zone permeability. Repeated earthquake activity is thus needed to maintain the permeability of fault zones in active natural geothermal fields. |
format |
Article in Journal/Newspaper |
author |
Agust Gudmundsson |
author_facet |
Agust Gudmundsson |
author_sort |
Agust Gudmundsson |
title |
Transport of Geothermal Fluids along Dikes and Fault Zones |
title_short |
Transport of Geothermal Fluids along Dikes and Fault Zones |
title_full |
Transport of Geothermal Fluids along Dikes and Fault Zones |
title_fullStr |
Transport of Geothermal Fluids along Dikes and Fault Zones |
title_full_unstemmed |
Transport of Geothermal Fluids along Dikes and Fault Zones |
title_sort |
transport of geothermal fluids along dikes and fault zones |
publisher |
MDPI AG |
publishDate |
2022 |
url |
https://doi.org/10.3390/en15197106 https://doaj.org/article/4e1ab7476386457ca98f30404cb41e87 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Energies, Vol 15, Iss 7106, p 7106 (2022) |
op_relation |
https://www.mdpi.com/1996-1073/15/19/7106 https://doaj.org/toc/1996-1073 doi:10.3390/en15197106 1996-1073 https://doaj.org/article/4e1ab7476386457ca98f30404cb41e87 |
op_doi |
https://doi.org/10.3390/en15197106 |
container_title |
Energies |
container_volume |
15 |
container_issue |
19 |
container_start_page |
7106 |
_version_ |
1766041425674240000 |