Exceptional Morainelike Deposits in Oregon
Introduction Exceptional morainelike deposits occur south of Columbia River between Willow Creek and John Day River and near Chenoweth Creek southwest of The Dalles (figure 1). The deposits are so peculiar in their occurrence and form and have such an important relationship in regard to the stream pattern of Columbia River and its tributaries that they deserve special attention. They were discovered in 1927, mapped in detail in 1930, and are herein described for the first time. The exceptional features of these deposits are their location and preservation. Geologists to whom they have been shown declare that they are true moraines or at least show morainelike topography. Accepting this conclusion, certain aspects of their location become difficult to explain, for the deposits are (1) almost on the brink of the great Columbia River canyon; (2) far removed from any possible source of mountain glaciers that might have deposited them; (3) . . .