"In the Late Cretaceous period (100 to 65 million years ago), southwestern Oregon was
inundated by a shallow seaway, which deposited a layer of sandstones and mudrocks
known as the Hornbrook Formation. These sedimentary rocks, which contain marine
fossils such as ammonites, gastropods, clams, and shark’s teeth, are exposed along the
flanks of the Klamath Mountains south and east of the Rogue River."
https://www.blm.gov/or/resources/recreation/tablerock/files/geol_intro.pdf
"Starting approximately 40 million years ago in the middle Eocene,[1] a braided river system called the "Ancestral Rogue River" flowed through the region where the Rogue Valley is now carved.[2] For about 2.1 million years,[1] the river deposited what is now known as the Payne Cliffs Formation by laying down a thin conglomerate, followed by arkosic sandstone and siltstone."
https://en.wikipedia.org/wiki/Upper_and_Lower_Table_Rock
I was hiking in my region and I was attracted to these rocks protruding from a field of grass. It was clear to me that they are relics of the Ancestral Rogue River.
Shoreline erosion undercutting is visible still horizontal.
Under this rock some homes of Cretaceous marine life.
The animals built shelter around them and the holes remains. A yellow bug is visible at the lower left.
This conglomerate may be 40 million years old. River cobbles have been re-cemented into a matrix rock over time. The cobbles tend to break along quartz crystal veins.
Flowing water agitates a pebble in a small hole creating circular depressions. This example (at center of photo) is about 8" in diameter. I found other examples, too.
Dan Shaw, The Vortex Detective.
Visit me in southern Oregon, where I guide tours of local vortex energy points.
DanShaw.com /
VortexMaps.com
