This unconformity divides the Carboniferous into the Mississippian and Pennsylvanian periods in North America.
Like the Kaskaskia sequence, Absaroka sedimentary deposits were dominated by detrital or siliclastic rocks.
In North America, the waters of the Absaroka sequence regressed (thinned) westward as the highlands to the east steadily eroded.
By the end of the period, the regression was complete, and the marine strata were superseded by extensive red bed deposition.
The smallest unit is described as a punctuated aggradational cycle (PAC) and represents between 225,000 and 100,000 years of sediment accumulation.