Geology of the Seal Rock Area

Seal RockA local resident of the central Oregon Coast found herself wishing for a pictorial guide that explained the geology of the area’s rocky shores, sea cliffs, and beaches to a layperson. Unable to find one, she eventually decided to learn as much as she could and compile the information.

Completed in November 2013 this document tells how the sedimentary rocks, basalt, marine terraces and sea cliffs in this area were formed and where they are visible. Sections on paleontology and buried forests are included, plus a discussion of earthquakes and tsunamis and how these forces may affect the geomorphology of the coast in the future. It features over 100 photos and includes maps, diagrams and references.

The area of focus is a seven-mile stretch of coast in Lincoln County, Oregon, from Ona Beach State Park south to Alsea Bay near Waldport, and about two miles inland to South Beaver Creek Road. The basalt of the Yachats area is also included, and the volcanic rocks at Yaquina Head, Cape Foulweather and Depoe Bay are briefly discussed.