Event Title
Determining the Origin of a Complex Gutter Cast from the Upper Ordovician Kope Formation, Northern Kentucky
Presentation Type
Poster/Portfolio
Presenter Major(s)
Geology
Mentor Information
Patricia Videtich
Department
Geology
Location
Kirkhof Center KC16
Start Date
10-4-2013 1:00 PM
End Date
10-4-2013 2:00 PM
Keywords
Physical Science
Abstract
An unusual sedimentary structure was collected from the Upper Ordovician Kope Formation in northern Kentucky. This structure, a gutter cast, is interpreted to have formed on a paleo seafloor by scouring and infilling during a large storm, possibly a hurricane. This gutter cast contains another (inner) gutter cast, which we believe is new to the literature. Thin section analysis indicates that the storm lag deposit in the inner gutter cast contains brachiopods, enchinoderms, crinoid stems, and trilobite fragments. Also within the inner gutter cast are two cephalopods with their long axes oriented parallel to a hypothesized sea floor current. Oxygen and carbon isotopic data for lime mud (´13C, -0.85 to -0.97 0 VPDB; ´18O, -5.82 to -6.01) and calcite cement (´13C, 0.42 to 0.75 ; ´18O -4.93 to -5.95) infilling the intraparticle porosity in the cephalopods indicate two sources of carbon and oxygen with the cement generally less negative in both isotopes than the lime mud.
Determining the Origin of a Complex Gutter Cast from the Upper Ordovician Kope Formation, Northern Kentucky
Kirkhof Center KC16
An unusual sedimentary structure was collected from the Upper Ordovician Kope Formation in northern Kentucky. This structure, a gutter cast, is interpreted to have formed on a paleo seafloor by scouring and infilling during a large storm, possibly a hurricane. This gutter cast contains another (inner) gutter cast, which we believe is new to the literature. Thin section analysis indicates that the storm lag deposit in the inner gutter cast contains brachiopods, enchinoderms, crinoid stems, and trilobite fragments. Also within the inner gutter cast are two cephalopods with their long axes oriented parallel to a hypothesized sea floor current. Oxygen and carbon isotopic data for lime mud (´13C, -0.85 to -0.97 0 VPDB; ´18O, -5.82 to -6.01) and calcite cement (´13C, 0.42 to 0.75 ; ´18O -4.93 to -5.95) infilling the intraparticle porosity in the cephalopods indicate two sources of carbon and oxygen with the cement generally less negative in both isotopes than the lime mud.