Importance of mechanical disaggregation in chemical weathering in a cold alpine environment, San Juan Mountains, Colorado

Abstract

Research Article| February 01, 1999 Importance of mechanical disaggregation in chemical weathering in a cold alpine environment, San Juan Mountains, Colorado Anthony R. Hoch; Anthony R. Hoch 1U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado 80303 Search for other works by this author on: GSW Google Scholar Michael M. Reddy; Michael M. Reddy 1U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado 80303 Search for other works by this author on: GSW Google Scholar James I. Drever James I. Drever 2University of Wyoming, P.O. Box 3006, Laramie, Wyoming 82071 Search for other works by this author on: GSW Google Scholar Author and Article Information Anthony R. Hoch 1U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado 80303 Michael M. Reddy 1U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado 80303 James I. Drever 2University of Wyoming, P.O. Box 3006, Laramie, Wyoming 82071 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1999) 111 (2): 304–314. https://doi.org/10.1130/0016-7606(1999)111<0304:IOMDIC>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Anthony R. Hoch, Michael M. Reddy, James I. Drever; Importance of mechanical disaggregation in chemical weathering in a cold alpine environment, San Juan Mountains, Colorado. GSA Bulletin 1999;; 111 (2): 304–314. doi: https://doi.org/10.1130/0016-7606(1999)111<0304:IOMDIC>2.3.CO;2 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 Weathering of welded tuff near the summit of Snowshoe Mountain (3660 m) in southwestern Colorado was studied by analyzing infiltrating waters in the soil and associated solid phases. Infiltrating waters exhibit anomalously high potassium to silica ratios resulting from dissolution of a potassium-rich glass that occurs as a trace phase in the rock. In laboratory experiments using rock from the field site, initial dissolution generated potassium-rich solutions similar to those observed in the field. The anomalous potassium release decreased over time (about 1 month), after which the dominant cation was calcium, with a much lower potassium to silica ratio.The anomalous potassium concentrations observed in the infiltrating soil solutions result from weathering of freshly exposed rock surfaces. Continual mechanical disaggregation of the rock due to segregation freezing exposes fresh glass to weathering and thus maintains the source of potassium for the infiltrating water. The ongoing process of creation of fresh surfaces by physical processes is an important influence on the composition of infiltrating waters in the vadose zone. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.