Macrofabrics and quartz microstructures confirm glacial origin of Sunnybrook drift in the Lake Ontario basin

Abstract

Research Article| February 01, 1990 Macrofabrics and quartz microstructures confirm glacial origin of Sunnybrook drift in the Lake Ontario basin William C. Mahaney William C. Mahaney 1Geomorphology and Pedology Laboratory, Department of Geography, Atkinson College, York University, North York, Ontario M3J 1P3, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information William C. Mahaney 1Geomorphology and Pedology Laboratory, Department of Geography, Atkinson College, York University, North York, Ontario M3J 1P3, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1990) 18 (2): 145–148. https://doi.org/10.1130/0091-7613(1990)018<0145:MAQMCG>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 William C. Mahaney; Macrofabrics and quartz microstructures confirm glacial origin of Sunnybrook drift in the Lake Ontario basin. Geology 1990;; 18 (2): 145–148. doi: https://doi.org/10.1130/0091-7613(1990)018<0145:MAQMCG>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 Macrofabric studies and scanning electron microscopic (SEM) analysis of sand grains in Sunnybrook diamicton confirm that it consists of lodgment and/or deformation till. Formation of Sunnybrook drift included deposition of glaciolacustrine mud and grounding of early Wisconsin ice, followed by rainout of glaciolacustrine sediments. Macrofabric and quartz microtexture analyses support a model of deposition of the middle member (Sunnybrook diamicton, unit b) as lodgment and/or deformation till. Macrofabrics show generally bimodal, and occasionally trimodal, orientations that in the lower part of the unit indicate progressive change in direction of ice movements: first westward to northwestward, and latger (in the middle and top of the unit) to the northwest. Quartz-grain microtextures show extensive crushing effects compatible with deposition by grounded active ice, as determined at other continental locales including Antarctica, Fenno-Scandia, northern Ontario, and Wellsch Valley, Saskatchewan. 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.