Formation of the Abitibi greenstone belt by arc-trench migration

Research Article| May 01, 1995 Formation of the Abitibi greenstone belt by arc-trench migration S. L. Jackson; S. L. Jackson 1Ontario Geological Survey, 933 Ramsey Lake Road, Sudbury, Ontario P3E 6B5, Canada Search for other works by this author on: GSW Google Scholar A. R. Cruden A. R. Cruden 2Department of Geology, University of Toronto, Mississauga, Ontario L5L 1C6, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information S. L. Jackson 1Ontario Geological Survey, 933 Ramsey Lake Road, Sudbury, Ontario P3E 6B5, Canada A. R. Cruden 2Department of Geology, University of Toronto, Mississauga, Ontario L5L 1C6, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1995) 23 (5): 471–474. https://doi.org/10.1130/0091-7613(1995)023<0471:FOTAGB>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 Email Permissions Search Site Citation S. L. Jackson, A. R. Cruden; Formation of the Abitibi greenstone belt by arc-trench migration. Geology 1995;; 23 (5): 471–474. doi: https://doi.org/10.1130/0091-7613(1995)023<0471:FOTAGB>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 Volcanic and plutonic rocks of Archean greenstone belts in the Abitibi subprovince become younger southward; plutonic rocks are ∼10–30 m.y. younger than volcanic rocks. The Abitibi greenstone belt has an upper crust of ∼2.75–2.70 Ga oceanic supracrustal assemblages and a middle crust of ∼2.70–2.68 Ga granitic and gneissic rocks. The greenstone belt upper crust is greenschist facies with upright structures and low reflectivity, and the middle crust is amphibolite facies with moderate to shallowly dipping structures and strong reflectivity. We propose that the age progression and crustal layering resulted from accretion of oceanic assemblages followed by extensive mid-crustal magmatism linked to southward migration of an arc-trench system. Thermal softening of the middle crust during magmatism caused ductile flow now represented by strong, mid-crustal reflectivity. Upward heat flow following magmatism caused late-tectonic (2.67–2.65 Ga) low-pressure metamorphism observed in the upper crust. 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.