Late Wisconsinan, pre-Valley Heads glaciation in the western Mohawk Valley, central New York, and its regional implications

Abstract

Research Article| August 01, 1991 Late Wisconsinan, pre-Valley Heads glaciation in the western Mohawk Valley, central New York, and its regional implications JOHN C. RIDGE; JOHN C. RIDGE 1Department of Geology, Tufts University, Medford, Massachusetts 02155 Search for other works by this author on: GSW Google Scholar DAVID A. FRANZI; DAVID A. FRANZI 2Center for Earth and Environmental Sciences, State University of New York College at Plattsburgh, Plattsburgh, New York 12901 Search for other works by this author on: GSW Google Scholar ERNEST H. MULLER ERNEST H. MULLER 3Department of Geology, Syracuse University, Syracuse, New York 13244-1070 Search for other works by this author on: GSW Google Scholar Author and Article Information JOHN C. RIDGE 1Department of Geology, Tufts University, Medford, Massachusetts 02155 DAVID A. FRANZI 2Center for Earth and Environmental Sciences, State University of New York College at Plattsburgh, Plattsburgh, New York 12901 ERNEST H. MULLER 3Department of Geology, Syracuse University, Syracuse, New York 13244-1070 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1991) 103 (8): 1032–1048. https://doi.org/10.1130/0016-7606(1991)103<1032:LWPVHG>2.3.CO;2 Article history First Online: 01 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 JOHN C. RIDGE, DAVID A. FRANZI, ERNEST H. MULLER; Late Wisconsinan, pre-Valley Heads glaciation in the western Mohawk Valley, central New York, and its regional implications. GSA Bulletin 1991;; 103 (8): 1032–1048. doi: https://doi.org/10.1130/0016-7606(1991)103<1032:LWPVHG>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 SocietyGSA Bulletin Search Advanced Search Abstract The history of late Wisconsinan, pre- Valley Heads glaciation (about 18-15.5 ka) implies that major glaciological controls, as well as overall climatic warming, influenced the pattern of deglaciation in the western Mohawk Valley. The Middleville Formation in the West Canada Valley contains the most complete record of pre-Valley Heads ice recession in central New York. The lithostratigraphic succession was determined through detailed mapping and logging of measured sections, provenance study of diamicton units, and the analysis of declination of detrital remanent magnetization (DRM) in laminated lacustrine silt and clay. The initial recession of southwest-flowing ice from the Adirondacks and at least two glacial re-advances of the Mohawk Lobe are recorded in these units. Glacial Lake Newport, impounded in the West Canada Valley during ice recession, attained levels that required ice-damming by coalescent Ontario and Mohawk Lobes and a subglacial outlet across the Mohawk Valley to the Susquehanna drainage basin. Initial ice recession in the Mohawk Valley was mostly by calving of active valley lobes in deep-water (up to 350 m) embayments and not by regional stagnation and simple downwasting. A shift of ice flow from the Adirondacks to ice flow from the Mohawk Lobe marks the development of low-land lobes during pre-Valley Heads time before the complete uncovering of the Adirondacks. The later dominance of the Ontario Lobe in Valley Heads time may have been the result of (1) a reduced supply of ice to the Mohawk Lobe from a diminished Adirondack ice dome, (2) changing ice-flow conditions in Quebec associated with an eastern St. Lawrence ice stream and calving bay, and (3) nonsynchronous surging of the Mohawk and Ontario Lobes as these lobes became fronted by deep lacustrine waters at different times. 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.