THE SHORT CREEK OOLITE (LOWER MISSISSIPPIAN) NEWTON COUNTY, ARKANSAS

A thin to massively cross-bedded oolitic limestone near the top of the Boone Formation (Osagean-Lower Mississippian) in the Parthenon Quadrangle, Newton County, Arkansas, was discovered during recent mapping supported by the STATEMAP Project. The oolitic outcrop belt is exposed along the Left Fork of Big Creek and covers nearly four square miles. The 5 to 15 foot oolitic interval occurs from approximately 80 feet to 5 feet below the top of the Boone Formation, marked by a chert conglomerate at some localities. The basal contact of the oolitic unit is not exposed.

We interpret the oolitic limestone at the top of the Boone Formation to be correlative with the Short Creek Oolite. The Short Creek Oolite is known from Kansas and Missouri and from several localities in northwest Arkansas. The identification of the Short Creek Oolite in the Parthenon Quadrangle is important because it is the southernmost and easternmost occurrence yet reported, and present mapping has greatly extended the spatial distribution of this facies. The Short Creek Oolite in Arkansas is interpreted as a grain flow deposit reflecting transportation of ooliths from their origin in Kansas-Missouri shoals. Initial megascopic data supports this conclusion. At one outcrop the deformation of thin oolitic beds surrounding a massive oolitic block suggests a possible olistolith detached from the shoal margin, similar to olistoliths reported previously from the lower Boone Formation in northwestern Arkansas.