Colloquium with Professor Jay Van Tassell, Oct. 9

Geology professor examines strange change in course of Wallowa River

October 2, 2014

The Enterprise Gravels

LA GRANDE, Ore. (EOU) – Why did the Wallowa River change its course and start flowing to the northwest into the Grande Ronde River?

Jay Van Tassell, Ph.D., professor of geology, will address this question during the first colloquium of the academic year at EOU Thursday, Oct. 9.

His presentation on “The Strange Change in the Course of the Wallowa River” begins at 4 p.m. in Ackerman Hall, Room 210. A reception will follow.

The gravel deposits that lie beneath the glacial moraines at Wallowa Lake and that outcrop in the Enterprise area were deposited approximately 1 to 2 million years ago by braided streams that flowed northward toward Hells Canyon.

Van Tassell examines the climate at the start of the Pleistocene ice ages, the pattern of block faulting in the area, and the changes in Hells Canyon associated with the spillover of Lake Idaho – the great lake that occupied the western Snake River Plain from approximately 9 to 2 million years ago – into the Salmon River drainage.

A list of related resources provided by Pierce Library is available for more in-depth information on this topic. Visit http://library.eou.edu/colloquium. To be added to the colloquium mailing list call 541-962-3316.