Across the crest of the Cincinnati Arch, within the Millan interval represents three "members" the formation, the carbonate ridg Bellevue, Corryville, and Mt. Auburn are each range parasequences Bellevue was deposited relatively shallow water, the Corryville in deeper relative shallow parasequence, close to water and the Mt. Auburn is deep water, and these make up one segyence that may not have well developed highstand systems tracts. In a general sense these three "members" a succession of facial. make up progressively deepening facies, but these faunal facies are repeated in reverse order upward through the Arnheim Formation from the deepwater carbonates in the base of the Sunset to shallow water with its "recurrent" Corryville fauna near its top, to the Oregonia with its fossil "hash" near its top.