Continental rifting and the Archean-Proterozoic transition

Research Article| March 01, 1987 Continental rifting and the Archean-Proterozoic transition Tim S. Blake; Tim S. Blake 1Department of Geology, University of Western Australia, Nedlands, Western Australia 6009, Australia Search for other works by this author on: GSW Google Scholar David I. Groves David I. Groves 1Department of Geology, University of Western Australia, Nedlands, Western Australia 6009, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information Tim S. Blake 1Department of Geology, University of Western Australia, Nedlands, Western Australia 6009, Australia David I. Groves 1Department of Geology, University of Western Australia, Nedlands, Western Australia 6009, Australia Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1987) 15 (3): 229–232. https://doi.org/10.1130/0091-7613(1987)15<229:CRATAT>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 Tim S. Blake, David I. Groves; Continental rifting and the Archean-Proterozoic transition. Geology 1987;; 15 (3): 229–232. doi: https://doi.org/10.1130/0091-7613(1987)15<229:CRATAT>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 In the Western Australian shield, the Norseman-Wiluna belt, dominated by lowermost sequences of deformed and metamorphosed basalts and komatiites, and the Fortescue Group, with successions of gently dipping, little-metamorphosed basalts and rare komatiites, are typical examples of Archean-style greenstones and Proterozoic-style platform sequences, respectively.Isotopic evidence, however, indicates that they are broadly coeval and both Archean (ca. 2.7 ±0.05 Ga), and geologic evidence suggests that both relate to continental rifting. Their contrasting volcanism and subsequent deformation are inferred to result from their positions relative to rift axes and the state of the basement, the Norseman-Wiluna belt representing a failed rift in stretched, relatively hot crust, and the Fortescue Group representing a continental basalt succession on thick, relatively cold crust. The Fortescue Group immediately follows a major period of crustal reworking and stabilization, whereas eruption of the greenstones of the Norseman-Wiluna belt was closely followed by such an event. Thus, the diachronous change in tectonic style from greenstones to platforms, the Archean-Proterozoic transition, in this case appears to relate to a finite period of stabilization of continental crust rather than to a fundamental change in tectonic style or process with time. 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.