It preserves fossils dating back to the Triassic period (Spathian substage).

[6] 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.

[5] The formation contains marine fossils, including crinoids, pelecypods, gastropods, worms, crustaceans, and the ammonoid Tirolites.

[3][1] The unit was first named as the Virgin limestone member of the Moenkopi Formation in 1922, by Harvey Bassler and John Reeside.