High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation
Abstract We address in situ serpentinization and mineral carbonation processes in oceanic lithosphere using integrated field magnetic measurements, rock magnetic analyses, superconducting quantum interference device (SQUID) microscopy, microtextural observations, and energy dispersive spectroscopy p...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-04-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2022GC010730 |
| _version_ | 1797638097781915648 |
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| author | Masako Tominaga Andreas Beinlich Eduardo A. Lima Paiden Pruett Noah R. Vento Benjamin P. Weiss |
| author_facet | Masako Tominaga Andreas Beinlich Eduardo A. Lima Paiden Pruett Noah R. Vento Benjamin P. Weiss |
| author_sort | Masako Tominaga |
| collection | DOAJ |
| description | Abstract We address in situ serpentinization and mineral carbonation processes in oceanic lithosphere using integrated field magnetic measurements, rock magnetic analyses, superconducting quantum interference device (SQUID) microscopy, microtextural observations, and energy dispersive spectroscopy phase mapping. A representative suite of ultramafic rock samples were collected, within the Atlin ophiolite, along a 100‐m long transect across a continuous outcrop of mantle harzburgite with several alteration fronts: serpentinite, soapstone (magnesite + talc), and listvenite (magnesite + quartz). Strong correlations between changes in magnetic signal strengths and amount of alteration are shown with distinctive contrasts between serpentinite, transitional soapstone, and listvenite that are linked to the formation and breakdown of magnetite. While previous observations of the Linnajavri ultramafic complex indicated that the breakdown of magnetite occurred during listvenite formation from the precursor soapstone (Tominaga et al., 2017, https://doi.org/10.1038/s41467-017-01610-4), results from our study suggest that magnetite destabilization already occurred during the replacement of serpentinite by soapstone (i.e., at lower fluid CO2 concentrations). This difference is attributed to fracture‐controlled flow of sulfur‐bearing alteration fluid at Atlin, causing reductive magnetite dissolution in thin soapstone zones separating serpentinite from sulfide‐mineralized listvenite. We argue that magnetite growth or breakdown in soapstone provides insight into the mode of fluid flow and the composition, which control the scale and extent of carbonation. This conclusion enables us to use magnetometry as a viable tool for monitoring the reaction progress from serpentinite to carbonate‐bearing assemblages in space and time with a caution that the three‐dimensionality of magnetic sources impacts the scalability of measurements. |
| first_indexed | 2024-03-11T12:58:43Z |
| format | Article |
| id | doaj.art-96c29ceaeb8b4feb9d22b53ffec49b42 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:58:43Z |
| publishDate | 2023-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-96c29ceaeb8b4feb9d22b53ffec49b422023-11-03T16:55:52ZengWileyGeochemistry, Geophysics, Geosystems1525-20272023-04-01244n/an/a10.1029/2022GC010730High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral CarbonationMasako Tominaga0Andreas Beinlich1Eduardo A. Lima2Paiden Pruett3Noah R. Vento4Benjamin P. Weiss5Department Geology and Geophysics Woods Hole Oceanographic Institution Woods Hole MA USADepartment of Earth Science Center for Deep Sea Research University of Bergen Bergen NorwayDepartment of Earth, Atmospheric and Planetary Sciences Massachusetts Institute of Technology Cambridge MA USADepartment of Geology and Geophysics Texas A&M University College Station TX USADepartment of Geology and Geophysics Texas A&M University College Station TX USADepartment of Earth, Atmospheric and Planetary Sciences Massachusetts Institute of Technology Cambridge MA USAAbstract We address in situ serpentinization and mineral carbonation processes in oceanic lithosphere using integrated field magnetic measurements, rock magnetic analyses, superconducting quantum interference device (SQUID) microscopy, microtextural observations, and energy dispersive spectroscopy phase mapping. A representative suite of ultramafic rock samples were collected, within the Atlin ophiolite, along a 100‐m long transect across a continuous outcrop of mantle harzburgite with several alteration fronts: serpentinite, soapstone (magnesite + talc), and listvenite (magnesite + quartz). Strong correlations between changes in magnetic signal strengths and amount of alteration are shown with distinctive contrasts between serpentinite, transitional soapstone, and listvenite that are linked to the formation and breakdown of magnetite. While previous observations of the Linnajavri ultramafic complex indicated that the breakdown of magnetite occurred during listvenite formation from the precursor soapstone (Tominaga et al., 2017, https://doi.org/10.1038/s41467-017-01610-4), results from our study suggest that magnetite destabilization already occurred during the replacement of serpentinite by soapstone (i.e., at lower fluid CO2 concentrations). This difference is attributed to fracture‐controlled flow of sulfur‐bearing alteration fluid at Atlin, causing reductive magnetite dissolution in thin soapstone zones separating serpentinite from sulfide‐mineralized listvenite. We argue that magnetite growth or breakdown in soapstone provides insight into the mode of fluid flow and the composition, which control the scale and extent of carbonation. This conclusion enables us to use magnetometry as a viable tool for monitoring the reaction progress from serpentinite to carbonate‐bearing assemblages in space and time with a caution that the three‐dimensionality of magnetic sources impacts the scalability of measurements.https://doi.org/10.1029/2022GC010730rock magnetismfluid‐rock interactioncarbonationoceanic lithosphereophiolite |
| spellingShingle | Masako Tominaga Andreas Beinlich Eduardo A. Lima Paiden Pruett Noah R. Vento Benjamin P. Weiss High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation Geochemistry, Geophysics, Geosystems rock magnetism fluid‐rock interaction carbonation oceanic lithosphere ophiolite |
| title | High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation |
| title_full | High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation |
| title_fullStr | High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation |
| title_full_unstemmed | High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation |
| title_short | High‐Resolution Magnetic‐Geochemical Mapping of the Serpentinized and Carbonated Atlin Ophiolite, British Columbia: Toward Establishing Magnetometry as a Monitoring Tool for In Situ Mineral Carbonation |
| title_sort | high resolution magnetic geochemical mapping of the serpentinized and carbonated atlin ophiolite british columbia toward establishing magnetometry as a monitoring tool for in situ mineral carbonation |
| topic | rock magnetism fluid‐rock interaction carbonation oceanic lithosphere ophiolite |
| url | https://doi.org/10.1029/2022GC010730 |
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