USGS1953
This work was done because niobium (columbium) has been found in several of the minerals and rocks of the Magnet Cove and Potash Sulphur Springs areas. Niobium is in demand for use in high-temperature and non-creep steels. The Magnet Cove and Potash Sulphur Springs areas are in central Arkansas between Malvern and Hot Springs. They are underlain by similar alkaline igneous complexes consisting of nepheline syenite, more basic alkaline rocks, and calcite rock or carbonatite. The igneous rocks intrude Paleozoic sedimentary rocks and are truncated by a Late Cretaceous erosion surface. At Magnet Cove deposits of rutile (TiO 2) occur within the igneous complex; two deposits of brookite (TiO 2 ) occur in quartzite of the Arkansas novaculite formation of probable Devonian and Mississippian age, near the margin of the complex. Perovskite (calcium titanate) occurs in several places in the igneous complex. Niobium is present in rutile, brookite, and perovskite, and also probably in other minerals not yet analyzed. In order to determine the distribution and average content of niobium in the larger titanium deposits, drill core and channel samples were analyzed for niobium, titanium, and other elements; and average figures were calculated. Concentrates and single crystals were also analyzed. Material from drill cores of perovskite-bearing magnetite-pyroxene rock on the Mo-Ti Corporation property was studied and analyzed. The Kimsey calcite quarry area was mapped, and channel samples and single crystals were analyzed. Channel samples from trenches on the Wilson prospect at Potash Sulphur Springs were analyzed. The areas studied contain large resources of titanium and niobium, of low grade. The major results of the analytical work are summarized in the following table.