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Early Cretaceous opening of the North Atlantic Ocean: Implications of the petrology and tectonic setting of the Fogo Seamounts off the SW Grand Banks, Newfoundland

2007; Geological Society of America; Volume: 119; Issue: 5-6 Linguagem: Inglês

10.1130/b26008.1

1943-2674

Georgia Pe‐Piper, David J. W. Piper, Lubomir F. Jansa, Ashely de Jonge,

Geological Formations and Processes Exploration

Research Article| May 01, 2007 Early Cretaceous opening of the North Atlantic Ocean: Implications of the petrology and tectonic setting of the Fogo Seamounts off the SW Grand Banks, Newfoundland Georgia Pe-Piper; Georgia Pe-Piper 1Department of Geology, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada Search for other works by this author on: GSW Google Scholar David J.W. Piper; David J.W. Piper 2Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, P.O. Box 1006, Dartmouth, Nova Scotia B2Y 4A2, Canada Search for other works by this author on: GSW Google Scholar Lubomir F. Jansa; Lubomir F. Jansa 2Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, P.O. Box 1006, Dartmouth, Nova Scotia B2Y 4A2, Canada Search for other works by this author on: GSW Google Scholar Ashley de Jonge Ashley de Jonge 3Department of Geology, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada Search for other works by this author on: GSW Google Scholar GSA Bulletin (2007) 119 (5-6): 712–724. https://doi.org/10.1130/B26008.1 Article history received: 23 Mar 2006 rev-recd: 29 Oct 2006 accepted: 09 Dec 2006 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 Georgia Pe-Piper, David J.W. Piper, Lubomir F. Jansa, Ashley de Jonge; Early Cretaceous opening of the North Atlantic Ocean: Implications of the petrology and tectonic setting of the Fogo Seamounts off the SW Grand Banks, Newfoundland. GSA Bulletin 2007;; 119 (5-6): 712–724. doi: https://doi.org/10.1130/B26008.1 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 Lower Cretaceous Fogo Seamounts and the J-Anomaly Ridge formed along the transform margin of the southwestern Grand Banks synchronous with volcanism on the adjacent continental shelf off southeastern Canada. This volcanism took place during the "nonvolcanic" rifting of Iberia from the Grand Banks. Chemical composition and radiogenic isotopes show that basalts from the seamounts range from mildly alkalic to mildly tholeiitic. The voluminous tholeiitic magmas resulted principally from decompression melting, and the ocean-island-basalt signature of the alkalic rocks also suggests upwelling of deeper asthenosphere. The distribution of the seamounts has been determined from magnetic, bathymetric, and seismic data. Some seamounts are flat-topped and resemble guyots in that they are capped by carbonate-platform rocks. The distribution of the seamounts suggests that they developed from edge-controlled convection in the upper mantle due to thermal and density gradients at the transform transition between the spreading ocean and the continental block of the Grand Banks. The thermal effects of the volcanism promoted mid-crustal partial melting and detachment faulting on the Grand Banks and the development of the asymmetric Grand Banks–Iberia rift system. The location of the volcanic centers was strongly influenced by crustal-scale strike-slip faulting. Although the Fogo Seamount chain thus has a different tectonic origin compared with many oceanic seamount chains, the young seamounts from another area, off the transform Californian margin, also show many geochemical similarities and may have a similar origin. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.