The Dockum is a Late Triassic geologic group found primarily on the Llano Estacado of western Texas and eastern New Mexico with minor exposures in southwestern Kansas, eastern Colorado, and Oklahoma panhandle. The Dockum reaches a maximum thickness of slightly over 650 m but is usually much thinner. The Dockum rests on an unconformity over the Anisian aged Anton Chico Formation.
Steamboat Butte, showing Dockum Group red beds at its base
The Carnian is the lowermost stage of the Upper Triassic Series. It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by the Norian. Its boundaries are not characterized by major extinctions or biotic turnovers, but a climatic event occurred during the Carnian and seems to be associated with important extinctions or biotic radiations. Another extinction occurred at the Carnian-Norian boundary, ending the Carnian age.
Alluvial plain red clays of the Travenanzes Formation, upper Carnian, the Dolomites, northern Italy
Brotheotrachyceras brotheus from the San Cassiano Formation, Val Badia, Dolomites, Southern Alps. This ammonoid is an index fossil for the lower Carnian
Carnian Earth