Geologic implications of seawater circulation through peridotite exposed at slow-spreading mid-ocean ridges

Research Article| April 01, 2002 Geologic implications of seawater circulation through peridotite exposed at slow-spreading mid-ocean ridges Timothy Schroeder; Timothy Schroeder 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Barbara John; Barbara John 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar B. Ronald Frost B. Ronald Frost 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Timothy Schroeder 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Barbara John 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA B. Ronald Frost 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Publisher: Geological Society of America Received: 08 Aug 2001 Revision Received: 07 Dec 2001 Accepted: 14 Dec 2001 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (4): 367–370. https://doi.org/10.1130/0091-7613(2002)0302.0.CO;2 Article history Received: 08 Aug 2001 Revision Received: 07 Dec 2001 Accepted: 14 Dec 2001 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Timothy Schroeder, Barbara John, B. Ronald Frost; Geologic implications of seawater circulation through peridotite exposed at slow-spreading mid-ocean ridges. Geology 2002;; 30 (4): 367–370. doi: https://doi.org/10.1130/0091-7613(2002)0302.0.CO;2 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 Peridotite denuded by tectonic extension and exposed at the seafloor adjacent to slow-spreading centers hosts hydrothermal circulation of seawater. The reaction of seawater with peridotite causes serpentinization, which generates a high-pH, strongly reducing fluid rich in methane and hydrogen, and is accompanied by as much as 40% volume expansion. Complete serpentinization of peridotite requires tectonic activity to open fluid paths sealed by volume expansion. Diffuse venting of serpentinization fluids causes lithification of calcareous ooze on the seafloor to chalk-like limestone. This may be the main mechanism of deposition of ophicarbonates common in ophiolites. The degree of induration is a function of the fluid flux through the sediment column. Calcareous ooze infiltrates faults and fractures and can be deformed following lithification. Focused venting of serpentinization fluids may lead to deposition of large chimneys composed of calcite, aragonite, and brucite, such as those in the recently documented Lost City vent field (30°N, Mid-Atlantic Ridge). Geophysical implications of serpentinization include (1) creation of magnetic anomalies due to growth of magnetite in serpentinite and (2) lowered seismic velocity. Integrated studies of geologic and geophysical effects of serpentinization may aid in a more complete understanding of the structure of oceanic lithosphere and the mechanisms that expose mantle peridotite at the seafloor. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.