K-Pg Boundary in Oregon

May 30, 2023


2022-1-30 Dead Cow trail (6)

Photographer: Jim Meissner 
Summary Authors: Jim Meissner; Jim Foster

Shown above (top photo) is a portion of the K-Pg Boundary (bluish layer) I observed near Ashland, Oregon. The rock outcrop (bottom photo) where I discovered this boundary possibly belongs to the Hornbrook Formation that dates from 100 million to 65 million years ago. Photos taken on January 30, 2022.

The K-Pg Boundary (Cretaceous-Paleogene Boundary) contains abundant evidence of a catastrophic asteroid impact, some 66 million years ago, that's believed to have caused the extinction of non-avian dinosaurs along with perhaps 75 percent of all other species living at that time. Evidence of this impact includes high levels of the element iridiumshocked quartz grains and glassy microtektites.


Ashland, Oregon Coordinates: 42.1946, 122.7095

Related Links:

Cretaceous-Paleogene Boundary