Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge
Abstract In 2016, temperature recorders were recovered, temperatures were measured, and fluid samples were collected from Vent 1, a high temperature (338°C) hydrothermal discharge site on the southern Cleft Segment of the Juan de Fuca Ridge. Coupled with previous sampling efforts, this collection re...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-11-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2020GC009360 |
| _version_ | 1797637936529801216 |
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| author | C. Geoffrey Wheat Robert A. Zierenberg Jennifer B. Paduan David W. Caress David A. Clague William W. Chadwick Jr. |
| author_facet | C. Geoffrey Wheat Robert A. Zierenberg Jennifer B. Paduan David W. Caress David A. Clague William W. Chadwick Jr. |
| author_sort | C. Geoffrey Wheat |
| collection | DOAJ |
| description | Abstract In 2016, temperature recorders were recovered, temperatures were measured, and fluid samples were collected from Vent 1, a high temperature (338°C) hydrothermal discharge site on the southern Cleft Segment of the Juan de Fuca Ridge. Coupled with previous sampling efforts, this collection represents a 32‐year record of discharge from a single chimney structure, the longest record to date. Remarkably, the fluid has remained brine‐dominated for more than three decades. This brine formed during phase separation and segregation prior to initial observations in 1984. Although the chloride concentration of the discharging fluid has decreased with time, the fluid temperature has remained nearly constant for at least 3.3 years and probably for 15 or even 22 years. Compositions of the discharging fluids are consistent with inputs from a deep‐sourced brine, which was last equilibrated at >400°C at a depth consistent with the base of the sheeted dikes and the brittle‐ductile transition. This brine mixed (diffusion or dispersion) with a likely non‐phase‐separated, hydrothermal fluid prior to discharge. A survey of hydrothermal endmember fluids with chlorinities in excess of 700 mmol/kg shows, with the exception of Fe, a single trend between major ion concentrations and chlorinity even though data are from a range of crustal compositions, spreading rates, and water and magma depths. Calculated deep‐sourced brines from hydrothermal fluid data are similar to data based on fluid inclusions and estimates of brine assimilation in magmas. A better understanding of brines is required given their potential duration of discharge and capacity for mobilizing metals. |
| first_indexed | 2024-03-11T12:55:25Z |
| format | Article |
| id | doaj.art-478febe97f024aff98424599e2dd09b8 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:55:25Z |
| publishDate | 2020-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-478febe97f024aff98424599e2dd09b82023-11-03T17:01:17ZengWileyGeochemistry, Geophysics, Geosystems1525-20272020-11-012111n/an/a10.1029/2020GC009360Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca RidgeC. Geoffrey Wheat0Robert A. Zierenberg1Jennifer B. Paduan2David W. Caress3David A. Clague4William W. Chadwick Jr.5Institute of Marine Sciences College of Fisheries and Ocean Sciences University of Alaska Fairbanks Moss Landing CA USADepartment of Earth and Planetary Sciences University of California Davis Davis CA USAMonterey Bay Aquarium Research Institute Moss Landing CA USAMonterey Bay Aquarium Research Institute Moss Landing CA USAMonterey Bay Aquarium Research Institute Moss Landing CA USACooperative Institute for Marine Resources Studies (CIMRS) Hatfield Marine Science Center Oregon State University Newport OR USAAbstract In 2016, temperature recorders were recovered, temperatures were measured, and fluid samples were collected from Vent 1, a high temperature (338°C) hydrothermal discharge site on the southern Cleft Segment of the Juan de Fuca Ridge. Coupled with previous sampling efforts, this collection represents a 32‐year record of discharge from a single chimney structure, the longest record to date. Remarkably, the fluid has remained brine‐dominated for more than three decades. This brine formed during phase separation and segregation prior to initial observations in 1984. Although the chloride concentration of the discharging fluid has decreased with time, the fluid temperature has remained nearly constant for at least 3.3 years and probably for 15 or even 22 years. Compositions of the discharging fluids are consistent with inputs from a deep‐sourced brine, which was last equilibrated at >400°C at a depth consistent with the base of the sheeted dikes and the brittle‐ductile transition. This brine mixed (diffusion or dispersion) with a likely non‐phase‐separated, hydrothermal fluid prior to discharge. A survey of hydrothermal endmember fluids with chlorinities in excess of 700 mmol/kg shows, with the exception of Fe, a single trend between major ion concentrations and chlorinity even though data are from a range of crustal compositions, spreading rates, and water and magma depths. Calculated deep‐sourced brines from hydrothermal fluid data are similar to data based on fluid inclusions and estimates of brine assimilation in magmas. A better understanding of brines is required given their potential duration of discharge and capacity for mobilizing metals.https://doi.org/10.1029/2020GC009360HydrothermalbrineCleft SegmentJuan de Fucamid‐ocean ridgewater‐rock reaction |
| spellingShingle | C. Geoffrey Wheat Robert A. Zierenberg Jennifer B. Paduan David W. Caress David A. Clague William W. Chadwick Jr. Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge Geochemistry, Geophysics, Geosystems Hydrothermal brine Cleft Segment Juan de Fuca mid‐ocean ridge water‐rock reaction |
| title | Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge |
| title_full | Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge |
| title_fullStr | Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge |
| title_full_unstemmed | Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge |
| title_short | Changing Brine Inputs Into Hydrothermal Fluids: Southern Cleft Segment, Juan de Fuca Ridge |
| title_sort | changing brine inputs into hydrothermal fluids southern cleft segment juan de fuca ridge |
| topic | Hydrothermal brine Cleft Segment Juan de Fuca mid‐ocean ridge water‐rock reaction |
| url | https://doi.org/10.1029/2020GC009360 |
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