3rd Stop:
Depoe Bay

Immediately over the roadside barrier we can stand on these Depoe Bay pillow basalts. The eroding surface is a breccia of clastic conglomerates and lavas. These spherical "pillow" shaped and jointed basalts have been eroded by the surf to form specatular tidal fountains. Pillow basalts form beneath water (typical of seafloor lavas) and are shaped by sudden cooling. This formation stands nearly twenty feet above high water and was probably uplifted by tectonic force and accreation from the ocean floor.

These headlands of Depoe Bay are composed of two formations which lay above the Depoe Bay seafloor basalt.The formations form a sandwich of sandstone between two layers of basalt. The Whale Cove Sandstone formation rests on the Depoe pillow basalt and above it is one of the Columbia R. flood basalts thought to have originated from the Frenchman Spring flow 15 m.y.a.

Depoe Bay headland formations

Created by STANLEY R. SANDERS, 1999
e-mail: sanders@transport.com