KUKU

KU ScholarWorks

  • myKU
  • Email
  • Enroll & Pay
  • KU Directory
    • Login
    View Item 
    •   KU ScholarWorks
    • Dissertations and Theses
    • Dissertations
    • View Item
    •   KU ScholarWorks
    • Dissertations and Theses
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Paleoenvironmental reconstruction of the Brady Soil in the Nebraska loess uplands using biosilicate and bioturbation analyses

    Thumbnail
    View/Open
    Woodburn_ku_0099D_13802_DATA_1.pdf (46.91Mb)
    Issue Date
    2014-12-31
    Author
    Woodburn, Terri Lee
    Publisher
    University of Kansas
    Format
    104 pages
    Type
    Dissertation
    Degree Level
    Ph.D.
    Discipline
    Geography
    Rights
    Copyright held by the author.
    Metadata
    Show full item record
    Abstract
    This dissertation takes a multiple-proxy approach to a paleoenvironmental reconstruction of the Holocene--Pleistocene Transition represented by the Brady Soil in the central Great Plains. To better understand this dynamic time of climate change, and to overcome the limitations of previous analyses using stable carbon isotope data, this study employs phytoliths to provide specific information on paleovegetation communities and quantitative shifts of plant taxa. Climatic indices based on both short- and large-cell phytolith frequencies add needed data on shifts of relative temperature (C3:C4 Grassland Ratio), water stress on plants (Bulliform Index), and soil moisture (from a proposed Soil Moisture Index). Analysis of short cell phytoliths reveals quantitative plant taxa shifts from Pooideae (C3) dominant grasses, with relatively large numbers of arboreal dicot spheres and a few Cyperaceae (sedge) present in a savannah or open woodland setting in the Bølling-Allerød climatic period (~14.6 ka to 12.9 ka), to a mixed, open grassland of Chloridoideae (C4) and Pooideae (C3) in the early Holocene. Stipa-type Pooideae, a cool-season grass preferring drier soil conditions, marks the onset of the Younger Dryas (~12.9 ka to 11.7 ka), which was previously not revealed in δ13C analysis. Brady Soil bioturbation was examined to provide a new proxy for paleoenvironmental conditions in addition to determining the effect of bioturbation particular to this soil on sediment transportation through the profile. Through macro- and micromorphology, particle size, soil color, and phytolith signatures, it was determined that invertebrate activity (primarily by cicada nymphs (Cicadidae) or burrower bugs (Cydnidae) of the Naktodemasis bowni ichnotaxon) was highly localized (diffusive mixing). Similar modern burrowers tend to be correlated with woody vegetation necessary throughout their lifecycle. Increased activity of cicada within the Bkb horizon corroborates phytolith reconstruction, indicating savannah to open woodland conditions during this time of Brady Soil pedogenesis. Non-local (advective) mixing is also prevalent due to vertebrate activity. Burrow and chamber construction, size parameters, and scratch traces indicate activity by prairie dog (Cynomys sp.) or ground squirrel (Spermophilus sp.).
    URI
    http://hdl.handle.net/1808/18405
    Collections
    • Dissertations [4475]
    • Geography & Atmospheric Science Dissertations and Theses [184]

    Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.


    We want to hear from you! Please share your stories about how Open Access to this item benefits YOU.


    Contact KU ScholarWorks
    785-864-8983
    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    785-864-8983

    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    Image Credits
     

     

    Browse

    All of KU ScholarWorksCommunities & CollectionsThis Collection

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Contact KU ScholarWorks
    785-864-8983
    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    785-864-8983

    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    Image Credits
     

     

    The University of Kansas
      Contact KU ScholarWorks
    Lawrence, KS | Maps
     
    • Academics
    • Admission
    • Alumni
    • Athletics
    • Campuses
    • Giving
    • Jobs

    The University of Kansas prohibits discrimination on the basis of race, color, ethnicity, religion, sex, national origin, age, ancestry, disability, status as a veteran, sexual orientation, marital status, parental status, gender identity, gender expression and genetic information in the University’s programs and activities. The following person has been designated to handle inquiries regarding the non-discrimination policies: Director of the Office of Institutional Opportunity and Access, IOA@ku.edu, 1246 W. Campus Road, Room 153A, Lawrence, KS, 66045, (785)864-6414, 711 TTY.

     Contact KU
    Lawrence, KS | Maps