Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 9, 1927 | Published
Journal Article Open

Age of the "Satsop" and the Dalles Formations of Oregon and Washington


Geologists have differed regarding the ages of the "Satsop" and the Dalles formations of the Columbia River Gorge region. Because of their bearing on the history of the Gorge and for other reasons their ages are important. During a brief investigation of these beds under the auspices of the Carnegie Institution of Washington, the writers secured fragmentary mammalian fossil remains from the Dalles formation representing not a Quaternary, but approximately an upper Miocene or lower Pliocene stage. This age determination is corroborated by the lithologic resemblance of the Dalles beds to the middle Neocene Ellensburg formation of central Washington, by the apparently similar relations of these two formations to the Columbia lavas, and by the induration of the Dalles beds, which is equal to that of lower or middle Neocene deposits of the west, but much greater than that of Quaternary formations.

Additional Information

© 1927 American Association for the Advancement of Science.

Attached Files

Published - 236.1.full.pdf


Files (340.7 kB)
Name Size Download all
340.7 kB Preview Download

Additional details

August 19, 2023
October 18, 2023