Landscape reduction by weathering in small Rhodesian watersheds

Abstract

Research Article| June 01, 1979 Landscape reduction by weathering in small Rhodesian watersheds L. B. Owens; L. B. Owens 1U.S. Department of Agriculture, Science and Education Administration, Coshocton, Ohio 43812 Search for other works by this author on: GSW Google Scholar J. P. Watson J. P. Watson 2Department of Agriculture, University of Rhodesia, Salisbury, Rhodesia Search for other works by this author on: GSW Google Scholar Author and Article Information L. B. Owens 1U.S. Department of Agriculture, Science and Education Administration, Coshocton, Ohio 43812 J. P. Watson 2Department of Agriculture, University of Rhodesia, Salisbury, Rhodesia Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1979) 7 (6): 281–284. https://doi.org/10.1130/0091-7613(1979)7<281:LRBWIS>2.0.CO;2 Article history First Online: 02 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 L. B. Owens, J. P. Watson; Landscape reduction by weathering in small Rhodesian watersheds. Geology 1979;; 7 (6): 281–284. doi: https://doi.org/10.1130/0091-7613(1979)7<281:LRBWIS>2.0.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 SocietyGeology Search Advanced Search Abstract Two small watersheds were studied to determine rates of dissolution of granite in Rhodesia. One watershed (0.91 km2) is hilly and has an annual rainfall of 1,220 mm, whereas the other (7.33 km2) is more nearly level and has an annual rainfall of 922 mm. Samples of drainage water were collected weekly for 2 yr. Water samples from the streams were analyzed for SiO2, A12O3, Fe2O3 (total Fe), K, Na, Ca, and Mg. Elemental levels were found to be relatively constant throughout the year. The flux of elemental removal was calculated from the streamflow rate and chemical concentrations.The loss of each constituent as a result of weathering could be determined after the chemical composition was determined for the parent rock and the weathered product. Knowing the amount of an element lost and its rate of net removal from the watershed, a rate of weathering for granite was calculated as 400 kg·ha−1 · yr−1 for the higher rainfall area, and 150 kg·ha−1 · yr−1 for the lesser rainfall area. These rates can also be expressed as 15.4 and 5.8 mm of rock weathered per 1,000 yr for the two areas, to produce 11.0 and 4.1 mm of soil, respectively. Thus, slope reduction on granite in Rhodesia is 4.4 and 1.7 mm/1,000 yr for the higher and lower rainfall areas, respectively. 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.