PROSPECTING FOR CRITICAL MINERALS AND RARE EARTH ELEMENTS FROM MARCELLUS SHALE IN THE WESTERN PORTION OF THE APPALACHIAN BASIN WITH NON-DESTRUCTIVE CORE CHARACTERIZATION

Identification of sources for domestic critical minerals and rare earth elements (CM/REE) has been deemed essential for the energy transition by the United States Department of Energy (DOE). The U.S. DOE’s National Energy Technology Laboratory’s (NETL) Geomaterials Characterization Laboratory has performed non-destructive core characterizations on energy-relevant rock cores for the past decade. During this time, NETL has published over 36 technical reports and made the associated data publicly available. Much of this work focuses on unconventional shale gas, subsurface carbon storage systems, and carbon-ore. These efforts provide cm-scale petrophysical and elemental data, photographic documentation, detailed core descriptions, and computed tomography (CT) data for each well. This provides a first phase prospecting resource for CM/REE resources and can provide a map for pin-pointing intervals and lithologies for further development.

Using historical core characterization data from 12 Marcellus wells from the western portion of the Appalachian Basin, this study builds an improved understanding of the chemostratigraphy of the basin. X-ray fluorescence (XRF) and CT images were used to determine lithologic intervals and potential ore bodies for further analysis, including benchtop digestion and inductively coupled plasma mass spectrometry (ICP-MS) to better understand the CM/REE enrichments. All 12 wells include 6 cm resolution elemental data from an Olympus Delta handheld XRF spectrometer, core petrophysical measurements (density, magnetic susceptibility, p-wave), and continuous medical CT images for the cored sections. Utilization of these resources enables the prospecting of potential well-to-well and cross basin targets.

The initial results of this analysis show the REE/CM enrichments are primarily within the redox sensitive organic black shale facies in the wells, indicated through enrichments in Ni, Cu, V, Mo, and Zn. We also find REE/CM enrichments within redox state transition zones where carbonate concretions form with large amounts of Ba, Fe, and S concurrent with enrichments in Ni and V. This occurs throughout the wells in Northwestern West Virginia and Southwest Pennsylvania in 2- to 3-ft intervals between the Cherry Valley Limestone and the organic-rich lower Marcellus.