CLASSIFICATION OF THE KIAMICHI FORMATION: FREDERICKSBURG OR WASHITA?

There are many authors who have come to the dilemma of where to place the Kiamichi Formation. The reason for the confusion is due to the conflict of the presence of an unconformity along the Kiamichi-Goodland contact. The unit contains many of the lithological characteristics that would define it as both the Fredericksburg Group and the Washita Group. It is also suggested that the Kiamichi Formation is a significant transitional point between the two groups. The Kiamichi Formation can only be found in the northern half of the studied area, and it increases in thickness rather quickly as it travels northward of said region, and to a lesser extent westward. There are other sparse locations where the Kiamichi is found and studied as well. The irrefutable fact is that the Kiamichi marks the end of the Fredericksburg and into the Washita, but in which member it should be included is controversial. Writers such as Denison et al. (2003) classify the Kiamichi at the bottom of the Washita Group, while others such as Sellards et al. (1932) chose to place it at the top of the Fredericksburg Group.