Role of melt supply in oceanic detachment faulting and formation of megamullions

Abstract

Research Article| June 01, 2008 Role of melt supply in oceanic detachment faulting and formation of megamullions Brian E. Tucholke; Brian E. Tucholke 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 Mark D. Behn; Mark D. Behn 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 W. Roger Buck; W. Roger Buck 2Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Jian Lin Jian Lin 3Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Geology (2008) 36 (6): 455–458. https://doi.org/10.1130/G24639A.1 Article history received: 24 Nov 2007 rev-recd: 07 Feb 2008 accepted: 19 Feb 2008 first online: 02 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 Brian E. Tucholke, Mark D. Behn, W. Roger Buck, Jian Lin; Role of melt supply in oceanic detachment faulting and formation of megamullions. Geology 2008;; 36 (6): 455–458. doi: https://doi.org/10.1130/G24639A.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 Normal faults are ubiquitous on mid-ocean ridges and are expected to develop increasing offset with reduced spreading rate as the proportion of tectonic extension increases. Numerous long-lived detachment faults that form megamullions with large-scale corrugations have been identified on magma-poor mid-ocean ridges, but recent studies suggest, counterintuitively, that they may be associated with elevated magmatism. We present numerical models and geological data to show that these detachments occur when ~30%–50% of total extension is accommodated by magmatic accretion and that there is significant magmatic accretion in the fault footwalls. Under these low-melt conditions, magmatism may focus unevenly along the spreading axis to create an irregular brittle-plastic transition where detachments root, thus explaining the origin of the enigmatic corrugations. Morphological and compositional characteristics of the oceanic lithosphere suggested by this study provide important new constraints to assess the distribution of magmatic versus tectonic extension along mid-ocean ridges. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.