Concentrically-zoned ironstone concretion in sandstone of the Morrison Formation, eastern flank of the Bighorn Mountains / western edge of the Powder River Basin, Wyoming, at the Sheridan College dinosaur fossil quarry, last week. The white stuff is caliche.
A quick post to celebrate the fact that as of three hours ago, Lily & I are back home in our condo in D.C. It’s been a great summer, and I have a gazillion more photos to share with you, but for now, this will have to serve as an appetizer.