Sponsor
Portland State University. Department of Earth Sciences
First Advisor
Marvin H. Beeson
Date of Publication
1979
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Geology
Department
Geology
Language
English
Subjects
Geology -- Oregon, Geochemistry -- Oregon
DOI
10.15760/etd.3095
Physical Description
1 online resource (162 p.)
Abstract
The North Fork stock is a composite intrusive body of Late Jurassic-Early Cretaceous age which outcrops in the Blue Mountains of northeastern Oregon. The upper 600 m of the intrusion are exposed over an area of approximately 36 km squared along the canyon walls of the North Fork of the John Day River in Grant and Umatilla counties. The stock intrudes metasediments, metavolcanics, and metagabbros associated with the Permian-Triassic Elkhorn Ridge Argillite. Contact metamorphism of the Elkhorn Ridge Argillite is developed to the hornblende-hornfels facies throughout most of the exposed area of this unit in the study area. The contact aureole of the North Fork stock extends away from the intrusive margins and ultimately grades into regionally metamorphosed greenschist- and amphibolite facies rocks. The metamorphic rocks exhibit a pronounced regional trend of foliation which is disrupted where it intersects intrusive contacts at steep angles.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
http://archives.pdx.edu/ds/psu/18108
Recommended Citation
Matty, David Joseph, "The geology and geochemistry of the North Fork stock, northeastern Oregon" (1979). Dissertations and Theses. Paper 3115.
https://doi.org/10.15760/etd.3095
Figure 5. Geologic Map of the North Fork Stock and Surrounding Area, northeastern Oregon
Figure 18 - Geologic Cross Sections A-A' and B-B' (1).pdf (556 kB)
Figure 18. Geologic Cross Sections A-A' and B-B'
Comments
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