REE DISTRIBUTION IN THE V-INTRUSIVE OF CENTRAL ARKANSAS

The "V"-Intrusive has been interpreted as a series of late Cretaceous syenite dikes with a coeval hydrothermal vein (D. R. Owens, 1967). These dikes are exposed adjacent to Lake Catherine, some 4 miles west of the well-known Magnet Cove intrusive complex in Arkansas. Assays from the 1960’s show this vein to be gold-bearing. This study was initiated with the goal of identifying the mineral phases associated with the gold. Determining the mineralogy of the gold-bearing phases is an essential step in estimating of the economics of the deposit. The rock texture, dominant minerals, and elemental composition of minerals were determined using a combination of Polarized Light Microscopy and Scanning Electron Microscopy (SEM) equipped with an Energy Dispersive Spectrometer (EDS). The vein is brecciated and includes the following minerals: chalcedony, quartz, fluorite, pyrite, and a notable amount of metamict, lath-shaped crystals. Many of the metamict crystals are primarily composed of calcium, fluorine, lanthanum, cerium and neodymium. With the high Rare Earth Element (REE) concentrations, the lath-shaped crystals have tentatively been identified as bastnâesite or synchesite. We have not been able to identify any gold in the available samples, however the high concentrations of REEs may prove to be valuable. With the increased demand for REEs in electronic devices and the limited supply in the United States, there is an economic incentive to identify and quantify these REE deposits.