Crustal magnetization reveals subsurface structure of Juan de Fuca Ridge hydrothermal vent fields

Research Article| November 01, 2002 Crustal magnetization reveals subsurface structure of Juan de Fuca Ridge hydrothermal vent fields Maurice A. Tivey; Maurice A. Tivey 1Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar H. Paul Johnson H. Paul Johnson 2School of Oceanography, University of Washington, Seattle, Washington 98195-7940, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Maurice A. Tivey 1Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA H. Paul Johnson 2School of Oceanography, University of Washington, Seattle, Washington 98195-7940, USA Publisher: Geological Society of America Received: 28 Mar 2002 Revision Received: 25 Jun 2002 Accepted: 09 Jul 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (11): 979–982. https://doi.org/10.1130/0091-7613(2002)0302.0.CO;2 Article history Received: 28 Mar 2002 Revision Received: 25 Jun 2002 Accepted: 09 Jul 2002 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 Maurice A. Tivey, H. Paul Johnson; Crustal magnetization reveals subsurface structure of Juan de Fuca Ridge hydrothermal vent fields. Geology 2002;; 30 (11): 979–982. 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 A near-bottom geophysical survey on the Endeavour segment of the northern Juan de Fuca Ridge shows that regions of well-defined low crustal magnetization are strongly correlated with both active and extinct submarine hydrothermal vent sites. In particular, at the Main Endeavour Field, we find discrete magnetization lows associated with each cluster of vents. Magnetization lows are directly centered beneath the vent clusters and have diameters of ∼100 m, which implies a near-vertical, narrow, pipe-like source region located directly beneath the surface expression of the vent edifices. Lows are also separated from each other by only 200 m, which further implies highly focused zones. Magnetization lows are also associated with inactive and extinct vent areas, which indicates that alteration of the magnetic minerals in the crust rather than (necessarily temporary) thermal demagnetization is the primary process responsible for the low magnetization. These narrow pipe-like bodies are highly characteristic of alteration pipes found in ophiolites and are indicative of hydrothermal fluid up-flow zones. Thus, each magnetization low may define an individual upwelling zone, with distinct subsurface plumbing and thermal structure. The crustal-magnetization patterns provide important constraints on the geometry of the subsurface plumbing beneath these hydrothermal vent systems. At the Main Endeavour Field, magnetization lows are distributed along the trend of the rift valley in a semiregular pattern with a spacing of ∼200 m, arguing that upward flow may be partitioned into regularly spaced intervals along the axis of the rift valley. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.