Magnetite in seafloor serpentinite--Some like it hot

Abstract

Research Article| February 01, 2014 Magnetite in seafloor serpentinite—Some like it hot Frieder Klein; Frieder Klein * 1Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA *E-mail: fklein@whoi.edu. Search for other works by this author on: GSW Google Scholar Wolfgang Bach; Wolfgang Bach 2Geosciences Department, University of Bremen, 28359 Bremen, Germany Search for other works by this author on: GSW Google Scholar Susan E. Humphris; Susan E. Humphris 1Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Wolf-Achim Kahl; Wolf-Achim Kahl 2Geosciences Department, University of Bremen, 28359 Bremen, Germany Search for other works by this author on: GSW Google Scholar Niels Jöns; Niels Jöns 2Geosciences Department, University of Bremen, 28359 Bremen, Germany Search for other works by this author on: GSW Google Scholar Bruce Moskowitz; Bruce Moskowitz 3Department of Earth Sciences, and Institute for Rock Magnetism, University of Minnesota, Minneapolis, Minnesota 55455, USA Search for other works by this author on: GSW Google Scholar Thelma S. Berquó Thelma S. Berquó 4Department of Physics, Concordia College, Moorhead, Minnesota 56562, USA Search for other works by this author on: GSW Google Scholar Geology (2014) 42 (2): 135–138. https://doi.org/10.1130/G35068.1 Article history received: 28 Aug 2013 rev-recd: 22 Oct 2013 accepted: 24 Oct 2013 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Frieder Klein, Wolfgang Bach, Susan E. Humphris, Wolf-Achim Kahl, Niels Jöns, Bruce Moskowitz, Thelma S. Berquó; Magnetite in seafloor serpentinite—Some like it hot. Geology 2014;; 42 (2): 135–138. doi: https://doi.org/10.1130/G35068.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Serpentinization of mantle peridotite generates molecular hydrogen that can be exploited by microorganisms to gain metabolic energy; however, the mechanisms that control hydrogen generation and magnetite formation during serpentinization remain poorly understood. We have examined partly to completely serpentinized peridotites recovered during the Ocean Drilling Program and find a remarkable variation in the abundance of magnetite. Some completely serpentinized peridotites have as much as 6.15 wt% magnetite, whereas others are nearly magnetite free (<0.04 wt%). Using isotopic, magnetic, and thermodynamic constraints, our study reveals a simple link between the abundance of magnetite, Fe content of brucite, and serpentinization temperature. Samples with abundant magnetite have Fe-poor brucite and were formed at temperatures of 200–300 °C, whereas magnetite-poor samples are associated with Fe-rich brucite and were formed at temperatures <∼200 °C. We demonstrate that, despite the small amounts of magnetite, abundant hydrogen is generated through Fe(III) hosted in serpentine, lending support to the idea that low- to moderate-temperature serpentinization can generate abundant hydrogen within the temperature limits of life. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.