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Stratigraphy

Dissertations and Theses

Geology -- Oregon -- Columbia County

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Geology

Stratigraphy, Diagenesis, And Depositional Environment Of The Cowlitz Formation (Eocene), Northwest Oregon, Leonard Carl Farr Jr. Jan 1989

Stratigraphy, Diagenesis, And Depositional Environment Of The Cowlitz Formation (Eocene), Northwest Oregon, Leonard Carl Farr Jr.

Dissertations and Theses

The Upper Eocene Cowlitz Formation is exposed in surface outcrops southwest of the town of Vernonia, in Columbia County, Oregon. The Cowlitz Formation also occurs in the subsurface of the Mist gas field where its Clark and Wilson (C and W) sandstone member (informal) acts as a natural gas reservoir, and its upper Cowlitz mudstone member (informal) acts as a cap rock. Surface exposures and continuous core were studied in order to determine Cowlitz Formation stratigraphy, and its depositional environment. Fresh core samples were also studied petrographically, and with a scanning electron microscope, in order to determine the effects of …


The Stratigraphy Of The Scappoose Formation, The Astoria Formation, And The Columbia River Basalt Group In Northwestern Columbia County, Oregon, Nancy Tompkins Ketrenos Jan 1986

The Stratigraphy Of The Scappoose Formation, The Astoria Formation, And The Columbia River Basalt Group In Northwestern Columbia County, Oregon, Nancy Tompkins Ketrenos

Dissertations and Theses

The study area is located in northwestern Columbia County, and covers an area of approximately 70 square kilometers. The purpose of the study was to investigate the possible correlation of the Scappoose and Astoria Formations and determine their stratigraphic relationship to the Columbia River Basalt Group through mapping, geochemistry and petrography.