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.

    GLOBAL HYDRLOGIC PERSPECTIVES ON THE MID-CRETACEOUS GREENHOUSE CLIMATE (APTIAN-ALBIAN)

    Thumbnail
    View/Open
    Suarez_ku_0099D_10576_DATA_1.pdf (7.501Mb)
    Issue Date
    2009-01-03
    Author
    Suarez, Marina B.
    Publisher
    University of Kansas
    Format
    190 pages
    Type
    Dissertation
    Degree Level
    Ph.D.
    Discipline
    Geology
    Rights
    This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
    Metadata
    Show full item record
    Abstract
    This dissertation examines the mid-Cretaceous greenhouse climate in the Aptian-Albian through the perspective of the global hydrologic cycle. Stable isotopic compositions of pedogenic and exposure surface carbonates presented herein provides low latitude constraints on the oxygen isotopic composition meteoric water during the Cretaceous. Petrographic and isotopic evidence from the Tlayua Formation of Mexico (18.5°N paleolatitude) establishes a shallow-water coastal environment that experienced supratidal conditions in which early meteoric diagenesis occurred. Trends in &delta18O vs. &delta13C space define meteoric calcite lines that are characterized by average &delta18O values of -7.78 / VPDB (Vienna Pee Dee Belemnite), and are used to calculate meteoric water compositions of -5.46 ± 0.56 / VSMOW (Vienna Standard Mean Ocean Water). Positive linear covariant trends are defined and used to estimate evaporative losses of vadose groundwater ranging from 8% to 12%. Meteoric sphaerosiderite lines from coastal wetland soils of the Caballos Formation in Colombia (2°N paleolatitude) have an average oxygen isotopic composition of -4.41 ± 0.37 / VPDB, and are used to calculate meteoric water compositions of -4.56 ± 0.38 / VSMOW. This new data is incorporated into a revised mass balance model that simulates components of the hydrologic cycle (precipitation , evaporation, oxygen isotopic composition of seawater, relative humidity and continental feedback). The model simulates the oxygen isotopic composition of water vapor and resulting precipitation. Results suggest precipitation flux and rates were greater in the mid-Cretaceous than modern precipitation flux and rates. Global average precipitation rates for the mid-Cretaceous range between 371 mm/year to 1154 mm/year greater than modern precipitation rates. Sensitivity testing of the model indicates that temperature, air mass origin and pathways, the oxygen isotopic composition of seawater in the low latitudes, and relative humidity are variables that have the potential to greatly affect the oxygen isotopic composition of precipitation, and need greater constraints. These results can be used to further constrain and improve more complex general circulation models to more accurately model the hydrologic cycle during the Aptian-Albian and for future greenhouse climates.
    URI
    http://hdl.handle.net/1808/5961
    Collections
    • Dissertations [4472]
    • Geology Dissertations and Theses [234]

    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