DETERMINING THE BASE OF THE RUSH SPRINGS AQUIFER UTILIZING DRILLER’S LOGS AND CORE SAMPLES

The Oklahoma Water Resources Board is conducting a hydrologic investigation on the Rush Springs Aquifer in western Oklahoma. The OWRB plans to produce a digital groundwater flow model to help allocate water rights and develop a water management plan. An accurate aquifer boundary is needed to help manage this important resource. As a result, a combination of driller’s lithologic description logs and geophysical logs were used to identify the base of the aquifer by the contact between the Rush Springs Sandstone and the Marlow formation. The Rush Springs Aquifer is composed of Permian-age very fine to fine-grained Rush Springs Sandstone, which is underlain by the Permian-age Marlow Formation consisting of interbedded sandstone, clay, and gypsum layers. Approximately 2000 driller logs, six geophysical logs, and multiple cores were analyzed to determine the base of the aquifer. Using Digital Elevation Models (DEM), the elevation of the aquifer base was calculated for the aquifer base to create a contour map. Preliminary analysis of the data revealed positive correlation of the aquifer’s base to the Anadarko Basin which agrees with the Becker and Runkle (1998) USGS study. Additionally, along rivers and streams the aquifer has eroded from fluvial processes. The findings showed how subsurface contour mapping of the base of the aquifer could be produced using driller’s logs which will be used in the development of the groundwater flow model for the area.