The Coastal Cliffs near Arch Rock

[AlanLichty]

The geology of the Oregon coast in the area between Cape Blanco and Brookings has little in common with the geology along the central and northern coastal areas. This region is the western edge of the Klamath Mountain formation that originally was part of an island arc that got pushed into the North American plate by the eastward movement of the Farallon plate between 130 to 260 million years ago. Some of the rocks in the Klamath Mountains are almost 500 million years old on the eastern side near the I-5 corridor. The exposed western edge exposes younger formations due to uplift.

The exposed cliff faces near the Arch Rock viewpoint in the Samuel Boardman Scenic Corridor show off layers that are quite different from the cliffs further north along the Pacific coastline.

C&C always welcome.

 

[Ben Egbert]

Thanks for the geology lesson and a nice image to go with it.

 

[JimFox]

I like the water motion in this, and I sure enjoyed the geology lesson also.

 

[Jameel Hyder]

Not a place I have visited. Interesting read on the geology of the place. Oh and a nice image too.

 

[AlanLichty]

Thanks for the geology lesson and a nice image to go with it.

I like the water motion in this, and I sure enjoyed the geology lesson also.

Not a place I have visited. Interesting read on the geology of the place. Oh and a nice image too.

Thanks for the comments - I like to learn about the geology of places I visit and the Oregon coast is a fun destination for that sort of learning experience.

Jameel - this is less than a mile from the trailhead for Secret Beach.

 

[Jon Buffington]

Very interesting!

 

[BlackRockArt]

The geology of the Oregon coast in the area between Cape Blanco and Brookings has little in common with the geology along the central and northern coastal areas. This region is the western edge of the Klamath Mountain formation that originally was part of an island arc that got pushed into the North American plate by the eastward movement of the Farallon plate between 130 to 260 million years ago. Some of the rocks in the Klamath Mountains are almost 500 million years old on the eastern side near the I-5 corridor. The exposed western edge exposes younger formations due to uplift.

The exposed cliff faces near the Arch Rock viewpoint in the Samuel Boardman Scenic Corridor show off layers that are quite different from the cliffs further north along the Pacific coastline.

View attachment 44191

C&C always welcome.

Alan, this is fascinating geology to read. When I drive on I-5 in California, I pick up different geological formations along the way.

Oliver

 

[AlanLichty]

Very interesting!

Thanks Jon.

Alan, this is fascinating geology to read. When I drive on I-5 in California, I pick up different geological formations along the way.

Oliver

Thanks Oliver - I have been hooked on figuring out why stuff looks like it does along roads I am driving on for decades now and carry along geology textbooks and reference materials in my RV in case something really interesting catches my eye.