Digital image processing applied to analysis of geophysical and geochemical data for southern Missouri

Linear gravity low across southern Missouri, underlain by low amplitude, low gradient aeromagnetic anomalies; due to variations in basement structures of rock types. Smoothed estimates of U, Th, and K derived from aerial gamma-ray data covering the Rolla Quadrangle were color coded and digitally overlaid onto a Landsat image, a shaded relief image of topography, and the geologic map of Missouri. Cambrian Lamotte Sandstone and Bonneterre Dolostone, which crop out adjacent to the Precambrian exposures, have higher values than the younger Cambrian and Ordovician carbonates, sandstones, and shales. Enrichment within the interfluvial plains probably due to presence of a clay-rich residuum.--Modified journal abstract.