Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California

Abstract

Research Article| January 01, 2008 Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California Daniel R. Muhs; Daniel R. Muhs 1U.S. Geological Survey, M.S. 980, Box 25046, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar James R. Budahn; James R. Budahn 1U.S. Geological Survey, M.S. 980, Box 25046, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Donald L. Johnson; Donald L. Johnson 2Department of Geography, University of Illinois, Urbana, Illinois 61801, USA Search for other works by this author on: GSW Google Scholar Marith Reheis; Marith Reheis 3U.S. Geological Survey, M.S. 980, Box 25046, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Jossh Beann; Jossh Beann 3U.S. Geological Survey, M.S. 980, Box 25046, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Gary Skipp; Gary Skipp 3U.S. Geological Survey, M.S. 980, Box 25046, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Eric Fisher; Eric Fisher 3U.S. Geological Survey, M.S. 980, Box 25046, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Julia A. Jones Julia A. Jones 4Department of Geosciences, 104 Wilkinson Hall, Oregon State University, Corvallis, Oregon 97331-5506, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2008) 120 (1-2): 106–126. https://doi.org/10.1130/B26218.1 Article history received: 09 Mar 2007 rev-recd: 22 Jun 2007 accepted: 25 Jun 2007 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 Daniel R. Muhs, James R. Budahn, Donald L. Johnson, Marith Reheis, Jossh Beann, Gary Skipp, Eric Fisher, Julia A. Jones; Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California. GSA Bulletin 2008;; 120 (1-2): 106–126. doi: https://doi.org/10.1130/B26218.1 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 There is an increasing awareness that dust plays important roles in climate change, biogeochemical cycles, nutrient supply to ecosystems, and soil formation. In Channel Islands National Park, California, soils are clay-rich Vertisols or Alfisols and Mollisols with vertic properties. The soils are overlain by silt-rich mantles that contrast sharply with the underlying clay-rich horizons. Silt mantles contain minerals that are rare or absent in the volcanic rocks that dominate these islands. Immobile trace elements (Sc-Th-La and Ta-Nd-Cr) and rare-earth elements show that the basalt and andesite on the islands have a composition intermediate between upper-continental crust and oceanic crust. In contrast, the silt fractions and, to a lesser extent, clay fractions of the silt mantle have compositions closer to average upper-continental crust and very similar to Mojave Desert dust. Island shelves, exposed during the last glacial period, could have provided a source of eolian sediment for the silt mantles, but this is not supported by mineralogical data. We hypothesize that a more likely source for the silt-rich mantles is airborne dust from mainland California and Baja California, either from the Mojave Desert or from the continental shelf during glacial low stands of sea. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when “Santa Ana” conditions prevail, caused by a high-pressure cell centered over the Great Basin. The eolian silt mantles constitute an important medium of plant growth and provide evidence that abundant eolian silt and clay may be delivered to the eastern Pacific Ocean from inland desert sources. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.