Carleton Bern, PhD
Biography
I am a Research Soil Scientist with the U.S. Geological Survey in the Colorado Water Science Center. My research examines the geochemical interactions between water, rock, and soil in both natural and human-managed systems. I specialize in using isotopes and geochemical tracers to answer questions of both basic and applied research. Areas of focus in my recent work include:
(1) Salinity in surface waters and soils of the semiarid western U.S.
(2) Water quality in relation to uranium mining
(3) Improving the 100-year-old methodology for quantifying soil geochemical development
(4) Applying stable isotopes of water to understanding water availability in the Headwaters of the Colorado and Gunnison River Basin as part of the USGS Next Generation Water Observing System (NGWOS)
Selected Recent Publications:
Bern, C.R., Holmberg, M., Kisfalusi, Z., 2020. Salt flushing, salt storage, and controls on selenium and uranium: A 31-year mass-balance analysis of an irrigated, semiarid valley. Journal of the American Water Resources Association: Paper No. JAWRA‐19‐0062‐P, https://doi.org/10.1111/1752-1688.12841 (Open access)
Bern, C.R., Holmberg, M.J., Kisfalusi, Z.D., 2020. Effects of John Martin Reservoir, Colorado on water quality and quantity: Assessment by chemical, isotopic, and mass-balance methods. Journal of Hydrology X, 7: 100051, https://doi.org/10.1016/j.hydroa.2020.100051 (Open access)
Bern, C.R., Walton-Day, K., Naftz, D., 2019. Improved enrichment factor calculations through principal component analysis: Examples from soils near breccia pipe uranium mines, Arizona, USA. Environmental Pollution, 248: 90-100, https://doi.org/10.1016/j.envpol.2019.01.122 (Open access)
Bern, C.R., Yesavage, T. 2018. Dual-phase mass balance modeling of small mineral particle losses from sedimentary rock-derived soils. Chemical Geology. https://doi.org/10.1016/j.chemgeo.2017.11.040
Bern, C.R., Thompson, A., Chadwick, O.A. 2015. Quantification of colloidal and aqueous element transfer in soils: The dual-phase mass balance model. Geochimica et Cosmochimica Acta. https://doi.org/10.1016/j.gca.2014.12.008
Bern, C.R., Clark, M.L., Schmidt, T.S., Holloway, J.M., McDougal, R.R., 2015. Soil disturbance as a driver of increased stream salinity in a semiarid watershed undergoing energy development.Journal of Hydrology, 524: 123-136, https://doi.org/10.1016/j.jhydrol.2015.02.020.
Science and Products
Brine Research Instrumentation and Experimental (BRInE) Lab
In the “Brine Research Instrumentation and Experimental (BRInE) Lab” task of the Oil and Gas Waters Project we produce and report water quality data in support of studies internal and external to the project. Conduct laboratory research to complement and provide tools to help answer basic...
Soil Disturbance Can Increase Stream Salinity in Semiarid Watersheds
Soil disturbance from construction of roads, pipelines, and well pads on naturally salt-rich soils was determined to be a potential factor resulting in increased salinity in a southern Wyoming stream. Construction can expose salt-rich soils in the subsurface to increased contact with rain and snow, thus mobilizing salts through runoff or water percolating into soils.
Effects of John Martin Reservoir on water quality and quantity: Assessment by chemical, isotopic, and mass-balance methods
Water quality and quantity can be influenced by transit through and storage in reservoirs. Assessing such effects can be challenging, however, because of mixing and residence times, and inter-annual net storage and release from both the reservoir itself and surrounding porosity. Here, different methodologies were used to assess the effect of John...
Bern, Carleton R.; Holmberg, Michael; Kisfalusi, Zachary Comment on “Particle fluxes in groundwater change subsurface rock chemistry over geologic time”
Over the last decade, studies at the Shale Hills Critical Zone Observatory (Shale Hills) have greatly expanded knowledge of weathering in previously understudied, shale-mantled terrains, as well as Earth's Critical Zone as a whole. Among the many discoveries made was the importance of redistribution and losses of micron-sized...
Bern, Carleton R.; Tiffany Yesavage Improved enrichment factor calculations through principal component analysis: Examples from soils near breccia pipe uranium mines, Arizona, USA
The enrichment factor (EF) is a widely used metric for determining how much the presence of an element in a sampling media has increased relative to average natural abundance because of human activity. Calculation of an EF requires the selection of both a background composition and a reference element, choices that can strongly influence the...
Bern, Carleton R.; Walton-Day, Katie; Naftz, David L. Colloid mobilization and seasonal variability in a semiarid headwater stream
Colloids can be important vectors for the transport of contaminants in the environment, but little is known about colloid mobilization at the watershed scale. We present colloid concentration, composition, and flux data over a large range of hydrologic conditions from a small watershed (Gordon Gulch) in the foothills of the Colorado Front Range....
Mills, Taylor J.; Suzanne P. Ancerson; Bern, Carleton R.; Aguirre, Arnulfo; Derry, Louis A. Iron isotope systematics of shale-derived soils as potentially influenced by small mineral particle loss
Loss of small mineral particles from soil has been suggested as a process that can produce net isotopic fractionation in the remaining soil. We extracted water dispersible colloids (WDCs) from bulk soil collected at the Susquehanna/Shale Hills Critical Zone Observatory (SSHO) and measured their Fe isotopic composition for comparison to published...
Bern, Carleton R.; Yesavage, Tiffany; Pribil, Michael Modifications to EPA Method 3060A to Improve Extraction of Cr(VI) from Chromium Ore Processing Residue-Contaminated Soils
It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from chromium ore processing residue (COPR). We modified various parameters of EPA 3060A toward understanding the transformation of COPR minerals in the alkaline extraction and improving extraction of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil. Aluminum...
Mills, Christopher T.; Bern, Carleton R.; Wolf, Ruth E.; Foster, Andrea L.; Morrison, Jean M.; Benzel, William M. Rare earth mineral potential in the southeastern U.S. Coastal Plain from integrated geophysical, geochemical, and geological approaches
We combined geophysical, geochemical, mineralogical, and geological data to evaluate the regional presence of rare earth element (REE)−bearing minerals in heavy mineral sand deposits of the southeastern U.S. Coastal Plain. We also analyzed regional differences in these data to determine probable sedimentary provenance. Analyses of heavy mineral...
Shah, Anjana K.; Bern, Carleton R.; Van Gosen, Bradley S.; Daniels, David L.; Benzel, William M.; Budahn, James R.; Ellefsen, Karl J.; Karst, Adam; Davis, Richard The Niobrara Formation as a challenge to water quality in the Arkansas River, Colorado, USA
Study regionArkansas River, east of the Rocky Mountains.Study focusCretaceous sedimentary rocks in the western United States generally pose challenges to water quality, often through mobilization of salts and trace metals by irrigation. However, in the Arkansas River Basin of Colorado, patchy exposure of multiple Cretaceous formations has made it...
Bern, Carleton R.; Stogner, Sr., Robert W. The distribution and composition of REE-bearing minerals in placers of the Atlantic and Gulf coastal plains, USA
Rare earth element (REE) resources are currently of great interest because of their importance as raw materials for high-technology manufacturing. The REE-phosphates monazite (light REE enriched) and xenotime (heavy REE enriched) resist weathering and can accumulate in placer deposits as part of the heavy mineral assemblage. The Atlantic and Gulf...
Bern, Carleton R.; Shah, Anjana K.; Benzel, William M.; Lowers, Heather A.