Purtuniq ophiolite, Cape Smith belt, northern Quebec, Canada: A reconstructed section of Early Proterozoic oceanic crust

Research Article| February 01, 1992 Purtuniq ophiolite, Cape Smith belt, northern Quebec, Canada: A reconstructed section of Early Proterozoic oceanic crust D. J. Scott; D. J. Scott 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Search for other works by this author on: GSW Google Scholar H. Helmstaedt; H. Helmstaedt 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Search for other works by this author on: GSW Google Scholar M. J. Bickle M. J. Bickle 2Department of Earth Sciences, Cambridge University, Downing Street, Cambridge CB2 3EQ, England Search for other works by this author on: GSW Google Scholar Author and Article Information D. J. Scott 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada H. Helmstaedt 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada M. J. Bickle 2Department of Earth Sciences, Cambridge University, Downing Street, Cambridge CB2 3EQ, England Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1992) 20 (2): 173–176. https://doi.org/10.1130/0091-7613(1992)020<0173:POCSBN>2.3.CO;2 Article history 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 D. J. Scott, H. Helmstaedt, M. J. Bickle; Purtuniq ophiolite, Cape Smith belt, northern Quebec, Canada: A reconstructed section of Early Proterozoic oceanic crust. Geology 1992;; 20 (2): 173–176. doi: https://doi.org/10.1130/0091-7613(1992)020<0173:POCSBN>2.3.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 The crustal part of a dismembered ophiolite is preserved in the structurally highest thrust sheets of the Early Proterozoic Cape Smith belt in northern Quebec, Canada. The rocks of the ophiolite represent two magmatic suites, each with a mantle source that is Nd isotopically distinct. The older suite comprises pillowed and massive volcanic rocks, sheeted dikes, dominantly gabbroic layered cumulate rocks, and rare plagiogranite sills and dikes in the volcanic sequence. This >5-km-thick tholeiitic suite is ca. 1998 Ma, and is compositionally and petrographically similar to rocks formed at modern oceanic spreading ridges. The younger suite (>4 km) comprises sheeted mafic dikes and layered ultramafic to mafic cumulate rocks that are similar to tholeiitic rocks found in modern plume- generated oceanic islands, such as Hawaii. The composite section is in excess of 9 km. Although the total thickness of the Purtuniq ophiolite may not be typical of that for oceanic crust formed at Early Proterozoic spreading ridges elsewhere, it does suggest that ancient ridge-formed crust was at least as thick as that in modern oceans. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.