Rates and time scales of clay-mineral formation by weathering in saprolitic regoliths of the southern Appalachians from geochemical mass balance

Abstract

Research Article| May 01, 2005 Rates and time scales of clay-mineral formation by weathering in saprolitic regoliths of the southern Appalachians from geochemical mass balance Jason R. Price; Jason R. Price 1Department of Geological Sciences, 206 Natural Sciences Building, Michigan State University, East Lansing, Michigan 48824-1115, USA Search for other works by this author on: GSW Google Scholar Michael A. Velbel; Michael A. Velbel 1Department of Geological Sciences, 206 Natural Sciences Building, Michigan State University, East Lansing, Michigan 48824-1115, USA Search for other works by this author on: GSW Google Scholar Lina C. Patino Lina C. Patino 1Department of Geological Sciences, 206 Natural Sciences Building, Michigan State University, East Lansing, Michigan 48824-1115, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Jason R. Price 1Department of Geological Sciences, 206 Natural Sciences Building, Michigan State University, East Lansing, Michigan 48824-1115, USA Michael A. Velbel 1Department of Geological Sciences, 206 Natural Sciences Building, Michigan State University, East Lansing, Michigan 48824-1115, USA Lina C. Patino 1Department of Geological Sciences, 206 Natural Sciences Building, Michigan State University, East Lansing, Michigan 48824-1115, USA Publisher: Geological Society of America Received: 17 Dec 2003 Revision Received: 17 Aug 2004 Accepted: 07 Sep 2004 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2005) 117 (5-6): 783–794. https://doi.org/10.1130/B25547.1 Article history Received: 17 Dec 2003 Revision Received: 17 Aug 2004 Accepted: 07 Sep 2004 First Online: 02 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 Jason R. Price, Michael A. Velbel, Lina C. Patino; Rates and time scales of clay-mineral formation by weathering in saprolitic regoliths of the southern Appalachians from geochemical mass balance. GSA Bulletin 2005;; 117 (5-6): 783–794. doi: https://doi.org/10.1130/B25547.1 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 Rates of clay formation in three watersheds located at the Coweeta Hydrologic Laboratory, western North Carolina, have been determined from solute flux-based mass balance methods. A system of mass balance equations with enough equations and unknowns to allow calculation of secondary-mineral formation rates as well as the more commonly determined primary-mineral dissolution rates was achieved by including rare earth elements (REE) in the mass balance.Rates of clay-mineral formation determined by mass balance methods have been used to calculate the time needed for a 5% (50 g kg−1) change in relative clay abundance in the saprolite at Coweeta; this corresponds to the "response time" of the clay mineral to, for example, a change in climate. The 5% change in relative clay abundance is the smallest change that can generally be detected using X-ray diffraction (XRD). Response times range from tens of thousands to hundreds of thousands of years. Extrapolating the Coweeta clay formation rates to other southern Appalachian regoliths, the time required to form measured clay abundances ("production times") in eastern Blue Ridge and Inner Piedmont regolith have been calculated. The production times of clay-mineral assemblages range from 2 k.y. to 2 m.y., with mean values ranging from 50 k.y. to 1 m.y. The results of this study are consistent with the arguments of Thiry (2000) that the best resolution of the paleoclimatic record in marine clay-rich sediments and mudrocks is ∼1 or 2 m.y. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.