Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems
Hydrothermal processes that lead to REE fractionation and redistribution are important for understanding water-rock interactions in geothermal energy resources and mineral deposits, and for determining how submarine hydrothermal activity affects the composition of oceanic crust. Much previous work o...
Main Authors: | , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
eScholarship, University of California
2019
|
Subjects: | |
Online Access: | https://escholarship.org/uc/item/4687r8sd |
id |
ftcdlib:oai:escholarship.org:ark:/13030/qt4687r8sd |
---|---|
record_format |
openpolar |
spelling |
ftcdlib:oai:escholarship.org:ark:/13030/qt4687r8sd 2023-06-18T03:41:26+02:00 Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems Fowler, Andrew PG Zierenberg, Robert A Reed, Mark H Palandri, James Óskarsson, Finnbogi Gunnarsson, Ingvi 2019-01-01 application/pdf https://escholarship.org/uc/item/4687r8sd unknown eScholarship, University of California qt4687r8sd https://escholarship.org/uc/item/4687r8sd public Rare earth elements Boiling Geothermal Hydrothermal Geochemical modeling Aqueous speciation Apatite partitioning Geochemistry Geology Physical Geography and Environmental Geoscience Geochemistry & Geophysics article 2019 ftcdlib 2023-06-05T17:59:40Z Hydrothermal processes that lead to REE fractionation and redistribution are important for understanding water-rock interactions in geothermal energy resources and mineral deposits, and for determining how submarine hydrothermal activity affects the composition of oceanic crust. Much previous work on REE transport and deposition has focused on submarine hydrothermal vents. We report REE concentrations in boiled fluids sampled from five subaerial, basalt-hosted geothermal fields, and explore controls on aqueous REE concentrations by ligand complexation and mineral supersaturation. Samples that boiled at pressures between 0.8 and 2.83 MPa were obtained from the Reykjanes, Svartsengi, Hellisheidi, and Nesjavellir geothermal systems in Iceland, and the Puna geothermal system in Hawaii. For comparison, we also report REE concentrations in hydrothermal fluids from the sediment hosted submarine Middle Valley hydrothermal system, which boiled at >250 MPa. The pH(25°C) values of the sampled subaerial geothermal fluids range from 3.94 to 6.77, and Cl concentrations range from near seawater (502 mmol/kg) to dilute (1.9 mmol/kg). La, Ce and Eu are the only REE present at levels above 5 picomole/kg (pmol/kg) in the boiled geothermal fluids; and there are notable CI chondrite normalized La and Eu anomalies in the saline fluids. REE concentrations in Middle Valley hydrothermal fluids fall within the typical range reported for submarine hydrothermal fluids and have around two orders of magnitude higher REE than the boiled subaerial geothermal fluids. Bulk samples of precipitates in pipes from the Reykjanes geothermal system have detectable REE, confirming that downhole fluids have lost REE during boiling and production of fluids for geothermal energy. Isenthalpic boiling models show that the proportions of La and Eu chloride complexes increase relative to other aqueous species as boiling progresses, attenuating the incorporation of La and Eu into precipitated well scale solids. Fluorapatite is calculated to precipitate on ... Article in Journal/Newspaper Iceland University of California: eScholarship Reykjanes ENVELOPE(-22.250,-22.250,65.467,65.467) Nesjavellir ENVELOPE(-21.251,-21.251,64.115,64.115) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Rare earth elements Boiling Geothermal Hydrothermal Geochemical modeling Aqueous speciation Apatite partitioning Geochemistry Geology Physical Geography and Environmental Geoscience Geochemistry & Geophysics |
spellingShingle |
Rare earth elements Boiling Geothermal Hydrothermal Geochemical modeling Aqueous speciation Apatite partitioning Geochemistry Geology Physical Geography and Environmental Geoscience Geochemistry & Geophysics Fowler, Andrew PG Zierenberg, Robert A Reed, Mark H Palandri, James Óskarsson, Finnbogi Gunnarsson, Ingvi Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
topic_facet |
Rare earth elements Boiling Geothermal Hydrothermal Geochemical modeling Aqueous speciation Apatite partitioning Geochemistry Geology Physical Geography and Environmental Geoscience Geochemistry & Geophysics |
description |
Hydrothermal processes that lead to REE fractionation and redistribution are important for understanding water-rock interactions in geothermal energy resources and mineral deposits, and for determining how submarine hydrothermal activity affects the composition of oceanic crust. Much previous work on REE transport and deposition has focused on submarine hydrothermal vents. We report REE concentrations in boiled fluids sampled from five subaerial, basalt-hosted geothermal fields, and explore controls on aqueous REE concentrations by ligand complexation and mineral supersaturation. Samples that boiled at pressures between 0.8 and 2.83 MPa were obtained from the Reykjanes, Svartsengi, Hellisheidi, and Nesjavellir geothermal systems in Iceland, and the Puna geothermal system in Hawaii. For comparison, we also report REE concentrations in hydrothermal fluids from the sediment hosted submarine Middle Valley hydrothermal system, which boiled at >250 MPa. The pH(25°C) values of the sampled subaerial geothermal fluids range from 3.94 to 6.77, and Cl concentrations range from near seawater (502 mmol/kg) to dilute (1.9 mmol/kg). La, Ce and Eu are the only REE present at levels above 5 picomole/kg (pmol/kg) in the boiled geothermal fluids; and there are notable CI chondrite normalized La and Eu anomalies in the saline fluids. REE concentrations in Middle Valley hydrothermal fluids fall within the typical range reported for submarine hydrothermal fluids and have around two orders of magnitude higher REE than the boiled subaerial geothermal fluids. Bulk samples of precipitates in pipes from the Reykjanes geothermal system have detectable REE, confirming that downhole fluids have lost REE during boiling and production of fluids for geothermal energy. Isenthalpic boiling models show that the proportions of La and Eu chloride complexes increase relative to other aqueous species as boiling progresses, attenuating the incorporation of La and Eu into precipitated well scale solids. Fluorapatite is calculated to precipitate on ... |
format |
Article in Journal/Newspaper |
author |
Fowler, Andrew PG Zierenberg, Robert A Reed, Mark H Palandri, James Óskarsson, Finnbogi Gunnarsson, Ingvi |
author_facet |
Fowler, Andrew PG Zierenberg, Robert A Reed, Mark H Palandri, James Óskarsson, Finnbogi Gunnarsson, Ingvi |
author_sort |
Fowler, Andrew PG |
title |
Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
title_short |
Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
title_full |
Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
title_fullStr |
Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
title_full_unstemmed |
Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
title_sort |
rare earth element systematics in boiled fluids from basalt-hosted geothermal systems |
publisher |
eScholarship, University of California |
publishDate |
2019 |
url |
https://escholarship.org/uc/item/4687r8sd |
long_lat |
ENVELOPE(-22.250,-22.250,65.467,65.467) ENVELOPE(-21.251,-21.251,64.115,64.115) |
geographic |
Reykjanes Nesjavellir |
geographic_facet |
Reykjanes Nesjavellir |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
qt4687r8sd https://escholarship.org/uc/item/4687r8sd |
op_rights |
public |
_version_ |
1769007007266766848 |