• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Master's Theses
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Master's Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Modeling of Silicate Mineral Weathering Reactions in an Alpine Basin of the Southern Sierra Nevada, California

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_hwr_0015_sip1_w.pdf
    Size:
    12.14Mb
    Format:
    PDF
    Download
    Author
    Shaw, Jeff Rolf
    Issue Date
    1997
    Advisor
    Bales, Roger C.
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    Mineral weathering reactions from a small, Sierran alpine watershed were modeled with a stoichiometric mole-balance method, using a multi-year record of streamflow and snowpack chemical analyses, and site-specific mineral compositions. Reaction modeling was intended to determine the dependence of mineral weathering stoichiometry on (1) time, (2) lithology /mineralogy, and (3) space. Thin sections were made from 13 Emerald Lake Watershed rock samples; mild hypogene alteration was identified in most samples, indicated by quartzsericite replacement of primary minerals and the presence of epidote and minor calcite. Electron microprobe analyses of thin sections provided basin-specific chemical compositions of major mineral species for reaction modeling. Time series arrays of input (snowpack) chemistry, and output (stream) chemistry were used to calculate molar balances of component ions in the watershed. Single weathering reactions were modeled first, to determine the most important species, then reactions were combined, using mineral compositions from different lithologies, to determine dependence on geology. Weathering reaction models were evaluated primarily by linear regression of modeled versus observed differences between snowmelt and streamflow chemistry. As modeled, relative molar quantities of silicate minerals dissolved through weathering did not change appreciably over the two years considered. Also, hornblende exerted influence on streamflow chemistry disproportionate to its volumetric presence; of all mineral species considered singly, it produced the lowest final error and the best fit of modeled versus observed ion concentrations. Weathering reactions using mineral compositions from the Emerald Lake Granodiorite, a mafic-rich unit in the lower elevations of the basin, best explained the chemical differences between snowpack and streamflow. Finally, different regions within the watershed, as delineated by the four main inflows, exhibited different weathering stoichiometries due to variations in their stream chemistry. A summary of quantitative chemical analyses for Emerald Lake Watershed minerals is appended, along with a listing and explanation of the computer program used to perform the mole-balance calculations.
    Type
    text
    Thesis-Reproduction (electronic)
    Degree Name
    M.S.
    Degree Level
    masters
    Degree Program
    Graduate College
    Hydrology and Water Resources
    Degree Grantor
    University of Arizona
    Collections
    Master's Theses

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.