Structure, geochemistry, and tectonic evolution of trench-distal backarc oceanic crust in the western Norwegian Caledonides, Solund-Stavfjord ophiolite (Norway)

Abstract

Research Article| July 01, 2012 Structure, geochemistry, and tectonic evolution of trench-distal backarc oceanic crust in the western Norwegian Caledonides, Solund-Stavfjord ophiolite (Norway) Harald Furnes; Harald Furnes † 1Department of Earth Science & Centre for Geobiology, University of Bergen, 5007 Bergen, Norway †E-mail: harald.furnes@geo.uib.no Search for other works by this author on: GSW Google Scholar Yildirim Dilek; Yildirim Dilek 2Department of Geology & Environmental Earth Science, Miami University, Oxford, Ohio 45056, USA3School of Earth Science and Mineral Resources, China University of Geosciences, Beijing 100083, China Search for other works by this author on: GSW Google Scholar Rolf Birger Pedersen Rolf Birger Pedersen 1Department of Earth Science & Centre for Geobiology, University of Bergen, 5007 Bergen, Norway Search for other works by this author on: GSW Google Scholar GSA Bulletin (2012) 124 (7-8): 1027–1047. https://doi.org/10.1130/B30561.1 Article history received: 07 Jun 2011 rev-recd: 10 Feb 2012 accepted: 16 Feb 2012 first online: 08 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 Harald Furnes, Yildirim Dilek, Rolf Birger Pedersen; Structure, geochemistry, and tectonic evolution of trench-distal backarc oceanic crust in the western Norwegian Caledonides, Solund-Stavfjord ophiolite (Norway). GSA Bulletin 2012;; 124 (7-8): 1027–1047. doi: https://doi.org/10.1130/B30561.1 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 SocietyGSA Bulletin Search Advanced Search Abstract The Late Ordovician (443 Ma) Solund-Stavfjord ophiolite complex in west Norway represents the youngest phase of oceanic crust formation in the western Norwegian Caledonides. It contains three structural domains with different crustal architecture that formed during two episodes of seafloor spreading evolution of a Late Ordovician marginal basin. The fossil oceanic crust of the younger episode contains pillow lavas, massive sheet flows, and hyaloclastites, NE-trending sheeted dikes, and high-level isotropic gabbros. The pillow lava versus massive sheet flow distribution and the occurrence of an extensive sheeted dike complex in the Solund-Stavfjord ophiolite complex are typical of in situ oceanic crust developed at modern intermediate-spreading mid-ocean ridges. The Solund-Stavfjord ophiolite complex lavas and dikes are composed predominantly of normal mid-ocean-ridge basalt (N-MORB) Fe-Ti basalts, and their trace-element patterns indicate a weak subduction influence. The Nd isotope data of these rocks suggest derivation of their magmas from an isotopically homogeneous melt source with no indication of continental crustal contamination. The Solund-Stavfjord ophiolite complex extrusive sequence contains phyllite interlayers and is conformably overlain by a continentally derived, quartz-rich metasandstone that is intercalated with sills of N-MORB basaltic lavas and shallow-level intrusions. The geochemical features of the upper-crustal rocks of the Solund-Stavfjord ophiolite complex indicate their formation from magmas in which the melt evolution involved only minor or no slab-derived fluids. The evolution of the Solund-Stavfjord ophiolite complex oceanic crust occurred in a short-lived (<20 m.y.), trench-distal, continent-proximal backarc basin, adjacent to the eastern margin of Greenland-Laurentia, during the closure of Iapetus. This inferred tectonic setting is reminiscent of the modern Andaman Sea at the eastern periphery of the Indian Ocean. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.