John Day Fossil Beds NM,Sheep Rock unit,Blue Basin,Turtle Cove strata, photo

Turtle Cove Strata

John Day Fossil Beds NM

Turtle Cove strata, a striking blue-green rock layer produced by millions of years of volcanic ash accumulation. Ignimbrites, which stand out in contrast, may be white, grey, pink, beige, brown or black depending on their composition and density.

Larger View