Graduation Semester and Year




Document Type


Degree Name

Master of Science in Earth and Environmental Science


Earth and Environmental Sciences

First Advisor

Merlynd K Nestell


The microfossil association of the Salesville Formation (Strawn Group, Missourian, Pennsylvanian) of small foraminifers, fusulinids, conodonts, ostracodes, holothurian sclerites, and rare radiolarians, has received very little study. The upper part of the Salesville Formation, as exposed at two sections near Mineral Wells, North-Central Texas, represents deposits of the upper Salesville major cycle and is the stratigraphic interval of interest in this study whose primary objective is to evaluate the biostratigraphic significance of the microfossil association found at the two exposures of this cycle. The distribution of the early Missourian microfaunas is used to interpret the depositional environments of the major cycle and its context within the upper part of the Strawn Group (lower part of the Missourian Stage, Pennsylvanian). Twelve new species of small foraminifers are described along with several updated descriptions of previously described species of small foraminifers and fusulinids. Other microfossils are discussed and illustrated, but not formally described. The upper part of the Salesville Formation is assigned herein to the biostratigraphic zones: fusulinid (Eowaeringella Zone), conodont (Idiognathodus cancellosus Zone), and ostracode (Kegelites dattonensis Zone). A correlation of two Salesville Formation sections is made along with suggested correlations of this interval to similar aged strata at other localities in North America using the microfossil association. The Salesville Formation contains a diverse microfossil association that allows excellent biostratigraphic correlation of its strata to other areas where similar aged Pennsylvanian strata are present. The geochemistry of abundant phosphate nodules present in the lower part of one of the sections is noted. The relative sea level change through the upper part of the Salesville major cycle at both studied localities is suggested in addition to an interpretation of the depositional environment.


Micropaleontology, Stratigraphy, Biostratigraphy


Earth Sciences | Physical Sciences and Mathematics


Degree granted by The University of Texas at Arlington