Surficial Geology, Quartz Arenite Geometry, and Depositional Environment of the Dakota Formation (Cretaceous) in the Dorrance Nw 7.5' Quadrangle, Eastern Russell County, Kansas

In the Dorrance NW 7.5' Quadrangle of central Kansas the surficial extent, geometric shapes, and distributions of the quartz arenite bodies were analyzed in order to evaluate the depositional environment of the Dakota Formation. Analysis indicates that a NW-SE trending quartz arenite body is present within the study area and has an arcuate-linear geometry. This body is composed of an amalgamation of several smaller intertongued bodies. The Dakota exposures studied contain quartz arenites that are mineral logically mature with little organic matter present. The cross-beds are all low-angle cross-beds. The paleocurrent directions reveal a bimodal-oblique pattern. Some Thallasinoides burrows were present at one site. Thus the quartz arenite body represents deposition near a delta but not within a delta. Deposition occurred within a linearclastic shoreline (barrier islands?). Therefore the trend of these quartz arenite bodies is perpendicular to what might normally be expected.