Late Amazonian glaciation at the dichotomy boundary on Mars: Evidence for glacial thickness maxima and multiple glacial phases

Abstract

Research Article| May 01, 2008 Late Amazonian glaciation at the dichotomy boundary on Mars: Evidence for glacial thickness maxima and multiple glacial phases James L. Dickson; James L. Dickson 1Department of Geological Sciences, Brown University, Providence, Rhode Island 02912, USA Search for other works by this author on: GSW Google Scholar James W. Head; James W. Head 1Department of Geological Sciences, Brown University, Providence, Rhode Island 02912, USA Search for other works by this author on: GSW Google Scholar David R. Marchant David R. Marchant 2Department of Earth Sciences, Boston University, Boston, Massachusetts 02215, USA Search for other works by this author on: GSW Google Scholar Geology (2008) 36 (5): 411–414. https://doi.org/10.1130/G24382A.1 Article history received: 07 Sep 2007 rev-recd: 28 Jan 2008 accepted: 06 Feb 2008 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation James L. Dickson, James W. Head, David R. Marchant; Late Amazonian glaciation at the dichotomy boundary on Mars: Evidence for glacial thickness maxima and multiple glacial phases. Geology 2008;; 36 (5): 411–414. doi: https://doi.org/10.1130/G24382A.1 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 Lineated valley fill (LVF) in fretted valleys at the dichotomy boundary has been interpreted as glacial in origin. Unknown are (1) the original thickness of the glacier ice, (2) the amount of ice-surface lowering, through sublimation and retreat, to its presently observed level, and (3) whether there were multiple periods of glaciation. We address these questions through analysis of an LVF glacial system. The elevation difference between the upper limit of a previous highstand and the current surface of the LVF at the study site is ~920 m. We interpret this difference to be the minimum amount of ice-surface lowering of the glacier system. Consistent with a general lowering of the ice surface are multiple moraines and/or trimlines, and changes in LVF flow patterns, as the ice retreated and decreased in thickness. The superposition of several lobes onto the current surface of the LVF indicates that a phase of alpine glaciation followed the lowering of the valley glacial system. These data suggest that the Late Amazonian glaciation that produced LVF in this region involved significantly larger amounts of ice than previously thought, and that subsequent alpine glaciation followed. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.