This report summarizes geologic and hydrologic data available for the Roubidoux Formation and the Gunter Sandstone Member of the Gasconade Formation, that are the most important aquifers in north Arkansas. It involved gathering and studying drill cuttings; preparing and interpreting both geologic and drilling logs to determine stratigraphic relations; and researching and tablulating water levels and yields reported by other workers. Well cuttings and strip logs were evaluated for 71 wells. Finally, digital models, utilizing Surfer Surface Mapping SystemsTM (version 6.02) by Golden Software, Inc. were built in which the data set was gridded by the Kriging method to allow extrapolation of contours drawn for geologic and hydrogeologic maps.

The report includes:

• Well location map
• Maps depicting mean annual precipitation and mean annual discharge of the Ozark Plateaus Region
• Correlation chart of Arkansas formations and Ozark Plateaus hydrologic units
• A discussion of the general geology of the Ozark Plateaus region
• Structural contour map of the Roubidoux Formation
• Structural contour map of the Gunter Sandstone Member of the Gasconade Formation
• Two maps depicting surface faults and inferred subsurface faults to depths of the Roubidoux-Gunter strata
• Isopach map of the Roubidoux Formation
• Isopach map of the Gunter Sandstone
• Map depicting static water level elevation for selected water wells
• Map depicting yields of selected water wells producing from the Roubidoux Formation
• Map depicting yields of selected water wells producing from both the Roubidoux and Gunter
• Discussion of water quality
• Histograms of water-quality data from selected wells in the study area
• Map depicting total dissolved solids of selected water wells
• Map depicting chloride concentration of selected water wells
• The Appendix contains a table presenting water-quality and water-well data for 174 wells used in the compilation of this report.

*Includes: 45 pages, 15 figures, 1 table

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