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 June 1929 | Published
Book Section - Chapter Open

A Neocene Erosion Surface in Central Oregon


A landscape, in the old age stage, termed the Ochoco Erosion Surface, bevels the Columbia lavas and Mascall formation of middle Miocene age at a large angle, and the Rattlesnake lower or middle Pliocene at a small angle, in parts of the Ochoco Range and the John Day country of central Oregon. North of the John Day country the Condon Erosion Surface, locally at least a peneplane, probably but at present not demonstrably the correlative of the Ochoco, truncates the Columbia lavas and perhaps The Dalles formation. A pause in the eventful diastrophic history of this part of the Northwest is apparently indicated by these features. Subsequently, during the present or Dayville cycle, the great gorges and valleys have been excavated.

Additional Information

© 1929 Carnegie institution of Washington. Presented before Geological Society of America, Cordilleran Section, at Berkeley, March 3, 1928.

Attached Files

Published - Buwalda_1929p1.pdf


Files (8.3 MB)
Name Size Download all
8.3 MB Preview Download

Additional details

August 19, 2023
January 14, 2024