Middle and late Proterozoic evolution of the northern Canadian Cordillera and Shield

Abstract

Research Article| March 01, 1979 Middle and late Proterozoic evolution of the northern Canadian Cordillera and Shield G. M. Young; G. M. Young 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada Search for other works by this author on: GSW Google Scholar C. W. Jefferson; C. W. Jefferson 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada Search for other works by this author on: GSW Google Scholar G. D. Delaney; G. D. Delaney 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada Search for other works by this author on: GSW Google Scholar G. M. Yeo G. M. Yeo 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada Search for other works by this author on: GSW Google Scholar Author and Article Information G. M. Young 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada C. W. Jefferson 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada G. D. Delaney 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada G. M. Yeo 1Geology Department, University of Western Ontario, London, Ontario N6A 5B7 Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1979) 7 (3): 125–128. https://doi.org/10.1130/0091-7613(1979)7<125:MALPEO>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation G. M. Young, C. W. Jefferson, G. D. Delaney, G. M. Yeo; Middle and late Proterozoic evolution of the northern Canadian Cordillera and Shield. Geology 1979;; 7 (3): 125–128. doi: https://doi.org/10.1130/0091-7613(1979)7<125:MALPEO>2.0.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 The thick Proterozoic succession of northwestern North America can be subdivided into three sequences: A (∼1.7 to ∼1.2 b.y.), B (∼1.2 to ∼0.8 b.y.), and C (∼0.8 to 0.57 b.y.). Deposition of the rocks of sequence A was followed by widespread mafic igneous activity about 1.2 b.y. ago. In the Cordilleran region these rocks were then folded during the Racklan (= Grenville?) orogeny. A second, mainly tensional, orogenic event, here called the “Hayhook orogeny, ” occurred near the time boundary between sequences B and C and may have culminated in continental fragmentation in Phanerozoic time. The older Proterozoic rocks of the Cordilleran region (sequences A and B) are considered to have been derived in part from rising orogens in the eastern part of the Canadian Shield. There is no definitive evidence of extensive oceanic areas in the Cordilleran region during the Proterozoic, but local small ocean basins may have existed at the time of deposition of sequence C. 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.