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The Hurricane Lentil in the lower part of the Landrum Member of the Cook Mountain Formation can be recognized for 170 miles along strike. This lentil lies at the base of the Landrum Member and is directly above the Wheelock Member. Three key beds, two bentonites and a fossil bed containing Plicatula filamentosa Conrad , are present at most exposures of the Hurricane Lentil. Sedimentary rocks of the Cook Mountain Formation are classified using the four common constituents: quartz, iron oxide, glauconite pellets, and clay. The abundant fossils in the Hurricane Lentil indicate deposition took place on the continental shelf in a quiet, open marine sea with a level bottom. The lower Hurricane Lentil was deposited in a relatively stable sea whereas the upper Hurricane Lentil was deposited in a regressive sea. / text

2 v. : ill., photos, graphs, tables, maps, 4 fold. charts in end pocket of v.1 ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 1981

2 v. : ill., photos, graphs, tables, maps, 4 fold. charts in end pocket of v.1 ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 1981

An almost complete sequence of middle and upper marine strata, informally designated in this study as the "Strata of Cascade Head", has yielded 334 species and varieties of fossil Foraminifera. The Foraminifera were collected from 38 localities in four stratigraphic sections measured along the Salmon River, Neskowin Creek, Cascade Head Road, and near the town of Three Rocks in the central Oregon Coast Range.

Foraminiferal data analysis and lithofacies analysis of a three-well transect through the Middle Eocene Yegua Formation in southeast Texas provide insights into the depositional and paleoenvironmental history of the Gulf of Mexico Basin. Vertical and downdip changes in the lithology of the Yegua Formation in the three wells represents the depositional environments of a delta system that prograded onto the continental shelf, updip from the shelf margin. Two progradational episodes and two marine transgressions of the Yegua delta system occurred within this interval of the Yegua Formation in southeast Texas. Factor analysis of benthic foraminiferal census data reveals five major recurring assemblages of benthic foraminifera. These assemblages, or biofacies, occupied environments ranging from marginal marine to normal marine, middle-to-outer shelf environments. The stratigraphic relationships of the five biofacies show paleoenvironmental complexities that are not readily apparent from the lithofacies analysis. Integration of lithologic data and nonforaminiferal paleontologic data with the foraminiferal data produces a detailed paleoenvironmental reconstruction of the Yegua shelf in dip direction. Comparison of the foraminiferal data from the Yegua Formation with modern foraminiferal data from the Gulf of Mexico indicates that several properties of modern foraminiferal assemblages are similar to the foraminiferal assemblages of the Yegua Formation. Generic predominance, species diversity, and planktic to benthic ratios of modem foraminiferal assemblages can be used to help determine the paleoenvironmental significance of the Yegua foraminiferal assemblages. These properties of modern foraminiferal assemblages are not exact analogs for Middle Eocene assemblages and should be applied with caution. / text