Physical Sciences and Mathematics Commons^™

Tephrostratigraphy Of The Middle Eocene Chumstick Formation, Cascade Range, Douglas County, Washington, Matthew John Mcclincy

Dissertations and Theses

This study outlines the ash (tuff) bed stratigraphy (tephrostratigraphy) in the middle Eocene Chumstick Formation of central Washington. The tuff beds provide local marker beds enabling interpretation of the stratigraphy and structure of the formation. The chemical signature of these units provides the basis on which the units can be traced over broad areas in the basin of deposition. Correlations of tuff beds were obtained over distances of 41 km.

The tephrostratigraphy of the Chumstick Formation consists of nineteen tuff marker beds. Seventeen of these units are chemically characterized in this study. Ten elements were used to fingerprint these tuff …

Biostratigraphy Of The Cowlitz Formation In The Upper Nehalem River Basin, Northwest Oregon, Neil B. Shaw

Dissertations and Theses

Examination of stream and roadcut exposures of the Cowlitz Formation allows the selection of measured representative 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.