Coyote Butte Limestone

Coyote Butte Limestone is a Permian formation in central Oregon exposed as isolated limestone buttes around Grindstone and Twelvemile creeks. First defined in 1943, it preserves unusually unaltered shallow-marine and reefal limestones deposited about 296 to 273 million years ago, when this region lay near the edge of Pangea. Though the outcrops are small, they are important for their diverse marine fossils, including corals, bryozoans, algae, fusulinids, brachiopods, crinoids, and rarer forms. As Oregon’s only discovered Paleozoic fossiliferous formation, it is significant both for interpreting how these limestone blocks were emplaced among younger oceanic rocks and for understanding marine ecosystems shortly before Olson’s Extinction.

Oregon · United States