From Abstract: Niobium (columbium) and titanium occur in several minerals and rocks of the Magnet Cove and Potash Sulphur Springs areas. Niobium is in demand for use in high-temperature and noncreep steels; titanium metal is becoming an important structural material. The Magnet Cove and Potash Sulphur Springs areas are in central Arkansas between the communities of Malvern and Hot Springs. They are underlain by similar alkalic igneous complexes consisting of nepheline syenite, more basic alkalic rocks, and calcite rock or carbonatite. The igneous rocks transect sedimentary rocks of Paleozoic age and were truncated by erosion of Late Cretaceous age.