Virgin Formation

The Virgin Formation consists of gray to yellowish gray to greenish gray limestone, occasionally fossiliferous, alternating with greenish yellow to reddish brown to gray shale or siltstone. The limestone beds are up to thick. Total thickness of the formation is up to . About 30% of the total section of the formation is limestone. The formation is interpreted as having been deposited in a near-shore shallow marine environment. The lower part shows cyclic sedimentation, while the upper part of the formation to the southeast was deposited in lagoons in an arid climate while marine deposition continued to the north. ==Fossils==

The formation contains marine fossils, including crinoids, pelecypods, gastropods, worms, crustaceans, and the ammonoid Tirolites. The latter is characteristic of the early Spathian stage of the Early Triassic. ==History of investigation==

The unit was first named as the Virgin limestone member of the Moenkopi Formation in 1922, by Harvey Bassler and John Reeside. ==See also==