Physical Sciences and Mathematics Commons^™

Encrustation Of Inarticulate Brachiopods On Scaphitid Ammonites And Inoceramid Bivalves From The Upper Cretaceous U. S. Western Interior, Neil H. Landman, Joshua S. Slattery, Peter J. Harries

School of Geosciences Faculty and Staff Publications

The inarticulate brachiopod Discinisca is a rare faunal element in the Upper Cretaceous of the U.S. Western Interior. We report two occurrences of encrustation of Discinisca on a scaphitid ammonite (scaphite) and several inoceramids from the lower Maastrichtian Baculites baculus/Endocostea typica Biozones of the Pierre Shale at two localities. Six specimens of Discinisca are present on a single specimen of Hoploscaphites crassus from east-central Montana. They occur along the furrow at the mature apertural margin. Because the brachiopods are restricted to the margin and do not occur on the rest of the shell, it is likely that they …

Strata-Bound Vein Array In The Basal Pierre Shale, Lake Francis Case, South Dakota, U.S.A, Harmon D. Maher Jr., Sarah Ferguson, Ryan Korth, Justine Marshall, Laura Pickett

Geography and Geology Faculty Publications

A distinctive strata-bound vein array occurs in the basal Pierre Shale exposed along the shores of Lake Francis Case, a reservoir on the Missouri River in south-central South Dakota. Typically 2–4 meters in thickness, the array consistently outcrops over a >50-km distance, a significant areal footprint. Ash layers define the upper and lower bounds of the vein array. Two, suborthogonal, preferred directions of vertical veins (northeast and southeast strike) define a regional pattern. By volume, vertical veins comprise 1–2% of the rock. Thinner, more discontinuous, and irregular horizontal veins also occur. Comparisons between array orientations and the joint/vein pattern in …

Paleoecology Of Late Cretaceous Methane Cold-Seeps Of The Pierre Shale, South Dakota, Kimberly Cynthia Handle

Dissertations, Theses, and Capstone Projects

Most investigations of ancient methane seeps focus on either the geologic or paleontological aspects of these extreme environments. In contrast, this thesis encompasses both disciplines to evaluate the paleoecology of these systems with greater detail than previously published either within the Western Interior Basin or elsewhere. This thesis addresses the following questions: 1) Are the changes in mineralogy of a seep discernable and predictable as a seep shifts from a clay-based environment to a carbonate-based environment? 2) What are the foundation organism(s) of Late Cretaceous methane cold-seeps? 3) Is there a correlation to the mineralogic changes and shifts in community …

Late Cretaceous Faunal Dynamics In The Western Interior Seaway: The Record From The Red Bird Section, Eastern Wyoming, Joshua Stephen Slattery

USF Tampa Graduate Theses and Dissertations

Studies examining bioevents (e.g., mass extinctions, faunal turnovers, diversification events) usually only scrutinize a short interval prior to such events, however, understanding their actual paleobiological implications requires a thorough understanding of the background conditions. The objective of this study is to document the background biodiversity dynamics in a single lithofacies of the Upper Cretaceous Pierre Shale that was deposited in an offshore setting of the Western Interior Seaway (WIS) and to place these changes into an environmental context. To assess the background biodiversity dynamics, the concretionary faunas of the Baculites eliasi through B. clinolobatus biozones of the Pierre Shale in …

Estimates Of Maximum Past Overburden For The Pierre Shale, Hayes Area, South Dakota, Thomas L. Rice

Science and Mathematics Faculty Publications

The Pierre Shale of the Northern Great Plains area of the United State is an Upper Cretaceous shale which was deposited in a marine environment. Geotechnically, the shale has been classified as an overconsolidated clay-shale. In South Dakota the Pierre Shale crops out extensively in the central and western portions of the state.

In this study an investigation was conducted for the purpose of clarifying and examining the existence of a discrepancy between geotechnically and geologically derived estimates of maximum past overburden for the Pierre Shale at Hayes, South Dakota.

The geological determination involved examining the topographic high points of …