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Abrupt landscape change post–6 Ma on the central Great Plains, USA

2012; Geological Society of America; Volume: 40; Issue: 10 Linguagem: Inglês

10.1130/g32919.1

1943-2682

Robert A. Duller, Alexander C. Whittaker, James B. Swinehart, John Armitage, Hugh D. Sinclair, Andrea Bair, Philip A. Allen,

Geological and Geochemical Analysis

Research Article| October 01, 2012 Abrupt landscape change post–6 Ma on the central Great Plains, USA Robert A. Duller; Robert A. Duller 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK2Department of Earth & Ocean Sciences, University of Liverpool, Liverpool L69 3GP, UK Search for other works by this author on: GSW Google Scholar Alexander C. Whittaker; Alexander C. Whittaker 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK Search for other works by this author on: GSW Google Scholar James B. Swinehart; James B. Swinehart 3School of Natural Resources, University of Lincoln, Lincoln, Nebraska 68583-0961, USA Search for other works by this author on: GSW Google Scholar John J. Armitage; John J. Armitage 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK4Institut de Physique du Globe de Paris, 1 rue Jussieu, 75238 Paris, cedex 05, France Search for other works by this author on: GSW Google Scholar Hugh D. Sinclair; Hugh D. Sinclair 5School of Geosciences, The University of Edinburgh, Grant Institute, Edinburgh EH9 3JW, UK Search for other works by this author on: GSW Google Scholar Andrea Bair; Andrea Bair 6Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309-0399, USA Search for other works by this author on: GSW Google Scholar Philip A. Allen Philip A. Allen 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Robert A. Duller 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK2Department of Earth & Ocean Sciences, University of Liverpool, Liverpool L69 3GP, UK Alexander C. Whittaker 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK James B. Swinehart 3School of Natural Resources, University of Lincoln, Lincoln, Nebraska 68583-0961, USA John J. Armitage 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK4Institut de Physique du Globe de Paris, 1 rue Jussieu, 75238 Paris, cedex 05, France Hugh D. Sinclair 5School of Geosciences, The University of Edinburgh, Grant Institute, Edinburgh EH9 3JW, UK Andrea Bair 6Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309-0399, USA Philip A. Allen 1Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK Publisher: Geological Society of America Received: 14 Oct 2011 Revision Received: 10 Apr 2012 Accepted: 15 Apr 2012 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2012 Geological Society of America Geology (2012) 40 (10): 871–874. https://doi.org/10.1130/G32919.1 Article history Received: 14 Oct 2011 Revision Received: 10 Apr 2012 Accepted: 15 Apr 2012 First Online: 09 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 Robert A. Duller, Alexander C. Whittaker, James B. Swinehart, John J. Armitage, Hugh D. Sinclair, Andrea Bair, Philip A. Allen; Abrupt landscape change post–6 Ma on the central Great Plains, USA. Geology 2012;; 40 (10): 871–874. doi: https://doi.org/10.1130/G32919.1 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 The principal control on landscape evolution in the central Great Plains of the United States over the past 10 m.y. is a contentious subject. New sedimentary data collected from Late Miocene Ogallala Group and Pliocene Broadwater Formation of the Nebraskan Great Plains demonstrates a twofold increase in the median grain size (from 20 mm to >40 mm) exported from the Rocky Mountains across the Miocene-Pliocene boundary. Paleoslope reconstructions derived from these data support the tilting of the Miocene Ogallala Group after 6 Ma, but demonstrate that the transport slope of the lower part of the unconformably overlying Pliocene succession is identical to the present-day slope. These data allow us to constrain the timing of differential uplift in the Great Plains to between 6 and 3.7 m.y.; the wavelength and short duration of this tilting are best explained by the initiation of localized dynamic topography. Our results also suggest a threefold to fourfold increase in specific stream power at this time, meaning that Pliocene rivers draining the central Rockies were considerably more competent than their Miocene predecessors. Incision during this period was not continuous. A significant episode of aggradation from 3.7 to 2.5 Ma is best explained by high rates of sediment supply relating to the warm, wet mid-Pliocene climate optimum. The modern pattern of incision on the Great Plains occurred from 2.5 Ma, and not from the end of the Miocene as is sometimes supposed, reflecting the onset of major Northern Hemisphere glaciation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.