Landscape modification in response to repeated onset of hyperarid paleoclimate states since 14 Ma, Atacama Desert, Chile

Abstract

Research Article| July 01, 2014 Landscape modification in response to repeated onset of hyperarid paleoclimate states since 14 Ma, Atacama Desert, Chile Teresa E. Jordan; Teresa E. Jordan † 1Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA †E-mail: [e-mail]. Search for other works by this author on: GSW Google Scholar Naomi E. Kirk-Lawlor; Naomi E. Kirk-Lawlor 1Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA Search for other works by this author on: GSW Google Scholar Nicolás P. Blanco; Nicolás P. Blanco 2Servicio Nacional de Geología y Minería, Avenida Santa María 0104, Santiago, Chile Search for other works by this author on: GSW Google Scholar Jason A. Rech; Jason A. Rech 3Department of Geology, Miami University, Oxford, Ohio 45056-1846, USA Search for other works by this author on: GSW Google Scholar Nicolás J. Cosentino Nicolás J. Cosentino 1Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2014) 126 (7-8): 1016–1046. https://doi.org/10.1130/B30978.1 Article history received: 31 Jul 2013 rev-recd: 31 Jan 2014 accepted: 20 Feb 2014 first online: 08 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 Teresa E. Jordan, Naomi E. Kirk-Lawlor, Nicolás P. Blanco, Jason A. Rech, Nicolás J. Cosentino; Landscape modification in response to repeated onset of hyperarid paleoclimate states since 14 Ma, Atacama Desert, Chile. GSA Bulletin 2014;; 126 (7-8): 1016–1046. doi: https://doi.org/10.1130/B30978.1 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 SocietyGSA Bulletin Search Advanced Search Abstract The landscape of the hyperarid Atacama Desert in northern Chile records extremely slow change on Earth's surface. Disputed ages for the onset of hyperaridity range from the late Paleogene through the Pleistocene. A long-term paleoclimate record is recorded in a nonmarine basin whose fill is primarily alluvial strata. For this setting, the primary proxies for climate state are the mineralogical and chemical composition of soil, which varies across a precipitation gradient, and the landforms and deposits of alluvial fans. During the most recent ∼15 million years, five climate-related landscape stages are resolved for the Pampa del Tamarugal sedimentary basin, with each successively younger stage inset lower in the local topography than its predecessor. The earliest landscape stage is expressed as a set of alluvial strata inherited from a time of arid or semi-arid climate, ca. 14–12 Ma. The younger four landscape stages generated a composite long-lasting exposure surface. Predominantly hyperarid conditions have persisted since ca. 12 ± 1 Ma, during which four intervals of arid to semi-arid climate occurred. Each wet interval was short lived, a million years or less, whereas some of the hyperarid periods were lengthy, 1–5 m.y. The hyperarid intervals were roughly 11–5.5 Ma, 4.5–4 Ma, 3.6–2.6 Ma, 2.2–1 Ma, and repeated intervals during the last 1 m.y. The onset of hyperaridity ca. 12 Ma likely reflects the growth of the Andes Mountains above a climate threshold. In contrast, sea surface temperature variability likely has controlled Atacama paleoclimate changes since the late Miocene. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.