ABSTRACT
More than 40 mineral species and a large number of varieties found in the Bethel sandstone of south-central Illinois are described in detail. The petrographic study of the sandstone involves a complete analysis of the size, shape, and roundness distributions of the sand grains. The interrelationships and the vertical and lateral variations of these parameters are discussed. The origin and age relationships of the cements and certain relationships of the foregoing properties of the formation to porosity, permeability, and oil recovery concludes the study of the physical properties of the Bethel sandstone. From a synthesis of these data it is concluded that most of the Bethel detritus in the basin came from Llanoria on the southwest and that only small fractions came from Ozarkia, the Wisconsin highlands, and the Canadian shield.
