The Capitan reef framework consists mainly of large calcareous sponges
(white), still in an oriented
living position with long axes perpendicular to reef trend. Calcareous sponges are encrusted by
Archaeolithoporella and marine cement (gray to black). Outcrop at the south spur of the mouth of
Walnut Canyon, just outside boundary of Carlsbad Caverns National Park, Eddy Co., NM.
Coin is 1.9 cm in diameter.
© Peter A. Scholle, 1999