• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • 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

    LATE PLEISTOCENE AND HOLOCENE ENVIRONMENTS IN THE GREAT BASIN.

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_8415081_sip1_m.pdf
    Size:
    7.655Mb
    Format:
    PDF
    Description:
    azu_td_8415081_sip1_m.pdf
    Download
    Author
    THOMPSON, ROBERT STEPHEN.
    Issue Date
    1984
    Keywords
    Geology, Stratigraphic -- Pleistocene.
    Geology, Stratigraphic -- Holocene.
    Paleobotany -- Great Basin -- Pleistocene.
    Paleobotany -- Great Basin -- Holocene.
    Paleoclimatology -- Great Basin -- Pleistocene.
    Paleoclimatology -- Great Basin -- Holocene.
    Great Basin.
    
    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
    Pollen and packrat midden data from the Great Basin indicate that the Pleistocene vegetation of the region was a combination of subalpine conifers on coarse substrates and steppe plants on finer valley bottom soils. While some of the modern dominants of the woodland zone were apparently absent from this region, other woodland and montane plants apparently persisted through the late Pleistocene. Some features of the Pleistocene environment, such as the large pluvial lakes, apparently disappeared by 12,000 yr B.P., while subalpine plants remained well below their modern elevational limits after 11,000 yr B.P. Limber pine and Rocky Mountain juniper apparently did not retreat from the lower mountain slopes until after 6500 yr B.P. Montane and woodland conifers, rare or absent in the region during the Wisconsin, dispersed across the region in the Middle Holocene. Other plants apparently did not reach their modern geographic limits until after 3000 yr B.P. The low elevational occurrences of subalpine species suggest that the late Pleistocene climate of the Great Basin was characterized by summer temperatures that were as much as 10°C cooler than those of today, and that there was some augmentation in the level of mean annual precipitation. The vegetational records provide no evidence of greater than modern levels of summer precipitation. While the persistence of montane plants at relatively low elevations implies cool or moist conditions through the Early Holocene, evidence from lacustrine systems suggests that there was a trend toward increasingly dry conditions during this period. The main period of migrations of woodland plants seems to slightly postdate the warmest and/or driest part of the Holocene, and these migrations may have been related to relatively high levels in summer temperatures, summer precipitation, and/or winter temperatures. Pollen data from a high elevation site, in conjunction with changes in water level in lower elevational lakes, suggest a return to cooler and/or moister conditions after 4000 yr B.P.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Geosciences
    Graduate College
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    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.