title: Rare earth element geochemistry of outcrop and core samples from the Marcellus Shale.
abstract: In this work, the geochemistry of the rare earth elements (REE) was studied in eleven outcrop samples and six, depth-interval samples of a core from the Marcellus Shale. The REE are classically applied analytes for investigating depositional environments and inferring geochemical processes, making them of interest as potential, naturally occurring indicators of fluid sources as well as indicators of geochemical processes in solid waste disposal. However, little is known of the REE occurrence in the Marcellus Shale or its produced waters, and this study represents one of the first, thorough characterizations of the REE in the Marcellus Shale. In these samples, the abundance of REE and the fractionation of REE profiles were correlated with different mineral components of the shale. Namely, samples with a larger clay component were inferred to have higher absolute concentrations of REE but have less distinctive patterns. Conversely, samples with larger carbonate fractions exhibited a greater degree of fractionation, albeit with lower total abundance. Further study is necessary to determine release mechanisms, as well as REE fate-and-transport, however these results have implications for future brine and solid waste management applications.
authors.affiliation: Department of Civil and Environmental Engineering, Carnegie Mellon University, PH 118L, Pittsburgh, PA 15213 USA.
authors.forename: Clinton W
authors.initials: CW
authors.lastname: Noack
authors.affiliation: URS, Washington Division, National Energy Technology Laboratory, Pittsburgh, PA 15236 USA.
authors.forename: Jinesh C
authors.initials: JC
authors.lastname: Jain
authors.affiliation: Department of Civil and Environmental Engineering, Carnegie Mellon University, PH 118L, Pittsburgh, PA 15213 USA ; Center for Environmental Implications of Nanotechnology (CEINT), Durham, USA.
authors.forename: John
authors.initials: J
authors.lastname: Stegmeier
authors.affiliation: National Energy Technology Laboratory, Pittsburgh, PA 15236 USA.
authors.forename: J Alexandra
authors.initials: JA
authors.lastname: Hakala
authors.affiliation: Department of Civil and Environmental Engineering, Carnegie Mellon University, PH 118L, Pittsburgh, PA 15213 USA.
authors.forename: Athanasios K
authors.initials: AK
authors.lastname: Karamalidis
keywords: Brine management; ICP-MS; Marcellus Shale; Material characterization; Rare earth elements; Waste disposal; X-ray diffraction