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Middle to Late Ordovician δ13C and 87Sr/86Sr stratigraphy in Virginia and West Virginia: implications for the timing of the Knox unconformity

Umholtz, Nicholas Moehle
http://rave.ohiolink.edu/etdc/view?acc_num=osu1400681920

Abstract Details

2014, Master of Science, Ohio State University, Geological Sciences.
The Knox unconformity represents a major break in Paleozoic carbonate deposition in the Appalachian Basin. The development of the angular unconformity has been attributed to both regional tectonism and eustasy. Better understanding the timing of the Knox unconformity allows for correlation to study areas outside of the Appalachian Basin, which may be used to elucidate the relative impact of these processes. Current biostratigraphic constraint on the timing and duration of the unconformity in the Virginia and West Virginia study area is based on a sparse fossil record and places the duration of the unconformity at around 10 mya. This study uses δ13C and 87Sr/86Sr chemostratigraphy to refine this timing through correlation to a more complete section farther north near the axis of the basin in Maryland. 87Sr/86Sr chemostratigraphy demonstrates that deposition resumed no later than 462 mya, in the Cahabagnathus. friendsvillensis conodont Zone, and refinement by δ13C correlation indicates that deposition likely ensued in the early part of this zone. 87Sr/86Sr chemostratigraphy in this study also establishes the maximum age for the uppermost preserved Knox Group strata (in this study area) at 473 mya, indicating a maximum possible duration of the Knox Unconformity in Virginia and West Virginia at 11 mya.
Matthew R. Saltzman, PhD (Advisor)
William I. Ausich, PhD (Committee Member)
Stig M. Bergström, PhD (Committee Member)
53 p.
Geology
Ordovician; chemostratigraphy; carbon isotope stratigraphy; strontium isotope stratigraphy; Knox unconformity; Blackford Formation

Recommended Citations

Citations

  • Umholtz, N. M. (2014). Middle to Late Ordovician δ13C and 87Sr/86Sr stratigraphy in Virginia and West Virginia: implications for the timing of the Knox unconformity [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1400681920

    APA Style (7th edition)

  • Umholtz, Nicholas. Middle to Late Ordovician δ13C and 87Sr/86Sr stratigraphy in Virginia and West Virginia: implications for the timing of the Knox unconformity . 2014. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1400681920.

    MLA Style (8th edition)

  • Umholtz, Nicholas. "Middle to Late Ordovician δ13C and 87Sr/86Sr stratigraphy in Virginia and West Virginia: implications for the timing of the Knox unconformity ." Master's thesis, Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1400681920

    Chicago Manual of Style (17th edition)

osu1400681920
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This open access ETD is published by The Ohio State University and OhioLINK.