BULK ELEMENTAL ANALYSIS OF THE LAMOTTE SANDSTONE USING NON-DESTRUCTIVE X-RAY FLUORESENCE

In response to concerns that increased levels of carbon dioxide are contributing to global climate change, the scientific community has been investigating ways to reduce anthropogenic carbon emissions. One method is geologic carbon sequestration: the injection of carbon dioxide into subsurface rock units for disposal. Southwest Missouri has no deep sedimentary basins, unmineable coal seams, or depleted oil and gas fields which are the conventional locations for geologic carbon sequestration, so an alternative is of interest.

The proposed target unit for injection in southwest Missouri is the Cambrian Lamotte Sandstone, the basal sedimentary unit in the area. As part of the Missouri Shallow Carbon Demonstration Project, the bulk elemental composition of the proposed injection unit was evaluated. This was done using non-destructive X-Ray Fluorescence (XRF). A library of standards to calibrate the XRF instrument was created and statistical models were used to determine facies based on major element composition. This determination was performed on five sandstone cores: four historical cores from the Missouri Department of Natural Resources’ McCracken Core Library and from one core onsite at the Shallow Carbon Demonstration Project. These facies were correlated using fence diagrams and ArcGIS. These data will be incorporated into the geochemical models of the proposed injection site and will help determine the feasibility of shallow carbon sequestration in southwest Missouri. This material is based upon work sponsored by the Department of Energy National Energy Technology Laboratory under Award Number DE-NT0006642 to City Utilities of Springfield, MO.