Skip to Main Content
Book Chapter

Correlation of Miocene flows of the Columbia River Basalt Group from the central Columbia River Plateau to the coast of Oregon and Washington

By
R. E. Wells
R. E. Wells
Search for other works by this author on:
R. W. Simpson
R. W. Simpson
Search for other works by this author on:
R. D. Bentley
R. D. Bentley
Search for other works by this author on:
M. H. Beeson
M. H. Beeson
Search for other works by this author on:
M. T. Mangan
M. T. Mangan
Search for other works by this author on:
T. L. Wright
T. L. Wright
Search for other works by this author on:
Published:
January 01, 1989

Nearly twenty flows of the Columbia River Basalt Group (CRBG) can be paleomagnetically and chemically correlated westward as far as 500 km from the Columbia Plateau in Washington, through the Columbia Gorge, to the Coast Range of Oregon and Washington. In the Coast Range near Cathlamet, Washington, the CRBG flow stratigraphy includes 10 flows of Grande Ronde Basalt (1 low-MgO R2 flow, 6 low-MgO N2 flows, 3 high-MgO N2 flows), 2 flows of Wanapum Basalt (both flows of Sand Hollow from the Frenchman Springs Member), and the Pomona Member of the Saddle Mountains Basalt. Elsewhere in the Coast Range, additional Grande Ronde Basalt flows, including flows of Winterwater or Umtanum, and additional Wanapum flows, including the flows of Ginkgo, have been reported. Thus at least 18 to 20 CRBG flows reached the coast region. Several of these distal flows have distinctive chemical and magnetic characteristics that are shared by nearby isolated intrusions in Coast Range sedimentary rocks, thus strongly supporting recent suggestions that these intrusions are invasive bodies fed by CRBG flows. Magnetization directions from several flows indicate 16 to 30° of clockwise rotation of the coast with respect to the plateau since middle Miocene time.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Special Papers

Volcanism and Tectonism in the Columbia River Flood-Basalt Province

Stephen P. Reidel
Stephen P. Reidel
Search for other works by this author on:
Peter R. Hooper
Peter R. Hooper
Search for other works by this author on:
Geological Society of America
Volume
239
ISBN print:
9780813722399
Publication date:
January 01, 1989

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal