Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 1986 Biostratigraphy of the Cowlitz Formation in the upper Nehalem River Basin, northwest Oregon Neil B. Shaw Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Geology Commons, and the Stratigraphy Commons Let us know how access to this document benefits ou.y Recommended Citation Shaw, Neil B., "Biostratigraphy of the Cowlitz Formation in the upper Nehalem River Basin, northwest Oregon" (1986). Dissertations and Theses. Paper 3654. https://doi.org/10.15760/etd.5538 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible:
[email protected]. ' AN ABSTRACT OF THE THESIS OF Neil B. Shaw for the Master of Science in Geology presented February 10, 1986. Title:Biostratigraphy of the Cowlitz Formation in the upper Nehalem River Basin, northwest Oregon APPROVED BY MEMBERS OF THE THESIS COMMITTEE: Ric::J,~ Thoms~~ Ch~:=~: Robert Van Atta Examination of stream and roadcut exposures of the Cowlitz Formation allows the selection of measured repre- sentative sections, and collection of fossils, from an area roughly defined by the intersection of the boundaries of Clatsop, Columbia, Tillamook and Washington counties in Oregon. The study defines the features of the local environment of deposition, correlates sections to derive a composite columnar section, and develops a checklist of species for both microfossils and megafossils of the Cowlitz Formation. A composite columnar section of 720 m, based on three stream sections and one roadcut section is " 2 presented.