Glacial Geology of the Reedy Glacier Area, Antarctica

Research Article| April 01, 1968 Glacial Geology of the Reedy Glacier Area, Antarctica JOHN H MERCER JOHN H MERCER Institute of Polar Studies, The Ohio State University, Columbus, Ohio Search for other works by this author on: GSW Google Scholar Author and Article Information JOHN H MERCER Institute of Polar Studies, The Ohio State University, Columbus, Ohio Publisher: Geological Society of America Received: 07 Jul 1966 Revision Received: 07 Sep 1967 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1968, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1968) 79 (4): 471–486. https://doi.org/10.1130/0016-7606(1968)79471:GGOTRG2.0.CO;2 Article history Received: 07 Jul 1966 Revision Received: 07 Sep 1967 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JOHN H MERCER; Glacial Geology of the Reedy Glacier Area, Antarctica. GSA Bulletin 1968;; 79 (4): 471–486. doi: https://doi.org/10.1130/0016-7606(1968)79471:GGOTRG2.0.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 SocietyGSA Bulletin Search Advanced Search Abstract The Reedy Glacier is an outlet from the East Antarctic Ice Sheet and flows through the Transantarctic Mountains to the Ross Ice Shelf. The higher parts of the mountains consist of plateau remnants at about 3000 to 3500 m elevation. A shallow depression in this surface is filled with 40 m of till underlain by mass-wasted sandstone bedrock. The basal till consists of granite fragments, probably derived from a hill nearby. The remainder has a clay-rich matrix and contains fragments of igneous, metamorphic and sedimentary rocks that were probably derived from the plateau surface. All the till except the superficial layer was apparently deposited by temperate, wet-based ice.In an ice-free area at 1400 m elevation alongside the Reedy Glacier, about halfway between the East Antarctic Ice Sheet and the Ross Ice Shelf, stranded lateral moraines indicate former ice levels 750 m, 400 m, and 260 m above the present glacier surface. Granitic boulders on the surface at 750 m are highly weathered, those at 400 m are moderately weathered, and those at 260 m are virtually unweathered. Toward the head of the glacier these three sets of stranded moraines progressively approach each other and are also closer to the present ice surface. There is no evidence that the ice of the Polar Plateau has varied much since its establishment.Alongside the Reedy Glacier at about 1500 m elevation, 90 m of ice-marginal lake sediments are exposed. At present virtually no meltwater is present. Inactive solifluction flows occur further up the glacier at about 2000 m elevation.The till sequence on the high plateau is believed to indicate progressive refrigeration and the replacement of a small, local glacier by a temperate, local ice cap that later became polar and dry-based. The temperate ice cap must have antedated the Antarctic Ice Sheet and probably existed during the Pliocene. The variations in thickness of the Reedy Glacier after it had become an outlet of the East Antarctic Ice Sheet are thought to have been determined mainly by the position of the grounding line of the Ross Ice Shelf, which was controlled by eustatic changes in sea level, so that the glacier thickened during northern hemisphere glaciations. The lake sediments and solifluction flows indicate "interglacial" conditions 6° to 10° C warmer than at present. 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.