Heretofore the Day Creek dolomite was supposed to be stratigraphically below the Cloud Chief gypsum. However, detailed work shows that it is above the Cloud Chief gypsum and below the Quartermaster formation. This fact is largely the reason for this paper.

In this paper the Blaine and younger Permian beds are discussed. The Blaine has four gypsum beds and the base of the Blaine is an exact horizon from its northernmost limits in Kansas south at least as far as Fairview, Oklahoma. Nearly all geologists who have traced the Blaine think that the Medicine Lodge member of the Blaine in Kansas is the equivalent of the Ferguson member of the Oklahoma section. It is suggested that, at least for northwestern Oklahoma, the Medicine Lodge member should be made the name of the lowest massive gypsum ledge of the Blaine and that very probably the term Ferguson should be dropped. Above the Medicine Lodge member are three distinct beds of massive gypsum, named, in ascending order: Shimer, Lovedale, and Haskew. The Medicine Lodge and Shimer names were o iginally used by Cragin. Lovedale and Haskew are names for beds which heretofore have not been named in northwestern Oklahoma.

The Cloud Chief gypsum is removed from its former position as a formation and placed as a member of the Whitehorse. The Whitehorse formation is divided into three members: Marlow, Rush Springs, and Cloud Chief. There are two important horizons in the Whitehorse where limestones or dolomites occur, one at the top of the Marlow and the other near the top of the Rush Springs. The dolomites at the top of the Marlow are called the Relay Creek dolomites, replacing the term "Greenfield," which is preoccupied. The dolomite near the top of the Rush Springs has been named Weatherford dolomite.

The Day Creek dolomite has two members: Upper and Lower Day Creek dolomites. These two dolomites are separated by 1-3 feet of brown to maroon shale. The Day Creek was formerly supposed to occur below the gypsums of the Cloud Chief. In this paper the Day Creek dolomite is placed above the Cloud Chief and underlying the Quartermaster formation.

All the Permian beds of Oklahoma and Kansas above the Day Creek are classified as belonging to the Quartermaster formation. The Kansas terms "Hackberry shale" and "Big Basin sandstone" are dropped, as these beds are correlated with the Quartermaster of Oklahoma.

In northwestern Oklahoma, there are no unconformities of recognizable size from the base of the Blaine to the highest exposures of the Quartermaster. The contacts between these formations are considered to be very nearly exact horizons and the formations are capable of sharp separation.

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