Publications
Listed below are publication products directly associated with the Geology, Energy & Minerals Science Center:
Filter Total Items: 1162
Tungsten skarn potential of the Yukon-Tanana Upland, eastern Alaska, USA—A mineral resource assessment
Tungsten (W) is used in a variety of industrial and technological applications and has been identified as a critical mineral for the United States, India, the European Union, and other countries. These countries rely on W imports mostly from China, which leaves them vulnerable to supply disruption. Consequently, the U.S. government has a current initiative to understand domestic resource potential
Authors
George N. D. Case, Garth E. Graham, Erin E. Marsh, Ryan Taylor, Carlin J. Green, Philip J. Brown, Keith A. Labay
The Confocal Laser Scanning Microscopy Working Group of the ICCP: Final report 2021
This report summarizes the activities and results of the Confocal Laser Scanning Microscopy (CLSM) working group (WG) of the International Committee for Coal and Organic Petrology (ICCP), from its inception in September, 2015, to the present day (September, 2021). The purpose of this report is to document the history of the working group and to compile and evaluate its results. The CLSM WG examine
Authors
Paul C. Hackley, Jolanta Kus, João Graciano Mendonça Filho, Andrew D. Czaja, Angeles Borrego, Dragana Životić
Reconstructing the paleoceanographic and redox conditions responsible for variations in uranium content in North American Devonian black shales
The uranium (U) content, and more recently, the ratio between 238U and 235U in black shales are commonly applied as a proxy to determine redox conditions and infer organic-richness. Uranium contents typically display a linear relationship with total organic carbon (TOC) in shales. This relationship is due to the processes and mechanisms responsible for the incorporation of U into the sediment duri
Authors
Michelle L. Abshire, Natascha Riedinger, John M. Clymer, Clint Scott, Silke Severmann, Stephen J. Romaniello, James O. Puckette
New insights into organic matter accumulation from high-resolution geochemical analysis of a black shale: Middle and Upper Devonian Horn River Group, Canada
Organic matter (OM) accumulation in organic matter-rich mudstones, or black shales, is generally recognized to be controlled by combinations of bioproductivity, preservation, and dilution. However, specific triggers of OM deposition in these formations are commonly difficult to identify with geochemical proxies, in part because of feedbacks that cause geochemical proxies for these controls to vary
Authors
Haolin Zhou, Nicholas B. Harris, Tian Dong, Korhan Ayranci, Jilu Feng, Benoit Rivard, Paul C. Hackley, Javin J. Hatcherian
Vitrinite reflectance analysis
Vitrinite is a maceral group (a set of organic matter types with similar properties and appearance) derived from the remains of woody material from vascular plants and is composed of the thermally evolved products of lignin and cellulose. Vitrinite is the dominant component of humic coal and is found as a minor component dispersed into sedimentary rocks, especially mudrocks, the primary source roc
Authors
Paul C. Hackley
Towards a holistic sulfate-water-O2 triple oxygen isotope systematics
Triple oxygen isotope (∆17O with δ18O) signals of H2O and O2 found in sulfate of oxidative weathering origin offer promising constraints on modern and ancient weathering, hydrology, atmospheric gas concentrations, and bioproductivity. However, interpretations of the sulfate-water-O2 system rely on assuming fixed oxygen-isotope fractionations between sulfate and water, which, contrastingly, are sho
Authors
Bryan Alan Killingsworth, Pierre Cartigny, Justin A. Hayles, Christophe Thomazo, Pierre Sansjofre, Virgil Pasquier, Stefan V. Lalonde, Pascal Philippot
Total alkali-silica diagram
The total alkali-silica (TAS) diagram is a scatterplot of the chemical concentrations of silica oxide (SiO2) versus total alkali-sodium oxide (Na2O) plus potassium oxide (K2O) – in volcanic rocks.
Authors
Ricardo A. Olea
Capacity assessment for Earth Monitoring, Analysis, and Prediction (EarthMAP) and future integrated monitoring and predictive science at the U.S. Geological Survey
Executive SummaryManagers of our Nation’s resources face unprecedented challenges driven by the convergence of increasing, competing societal demands and a changing climate that affects the stability, vulnerability, and predictability of those resources. To help meet these challenges, the scientific community must take advantage of all available technologies, data, and integrative Earth systems mo
Authors
Jennifer L. Keisman, Sky Bristol, David S. Brown, Allison K. Flickinger, Gregory L. Gunther, Peter S. Murdoch, MaryLynn Musgrove, John C. Nelson, Gregory D. Steyer, Kathryn A. Thomas, Ian R. Waite
By
Ecosystems Mission Area, Water Resources Mission Area, Science Synthesis, Analysis and Research Program, Science Analytics and Synthesis (SAS) Program, Energy Resources Program, Geology, Energy & Minerals Science Center, Oklahoma-Texas Water Science Center, Oregon Water Science Center, Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Wetland and Aquatic Research Center
Oil and gas wastewater components alter streambed microbial community structure and function
The widespread application of directional drilling and hydraulic fracturing technologies expanded oil and gas (OG) development to previously inaccessible resources. A single OG well can generate millions of liters of wastewater, which is a mixture of brine produced from the fractured formations and injected hydraulic fracturing fluids (HFFs). With thousands of wells completed each year, safe manag
Authors
Denise M. Akob, Adam Mumford, Andrea Fraser, Cassandra Rashan Harris, William H. Orem, Matthew S. Varonka, Isabelle M. Cozzarelli
Random forest
This entry defines and discusses the random forest machine learning algorithm. The algorithm is used to predict class or quantities for target variables using values of a set of predictor variables. It uses decision trees that are generated from bootstrap sampling of the training data set to create a "forest". The entry discusses the algorithm steps, the interpretative tools of the resulting mode
Authors
Emil D. Attanasi, Timothy Coburn
Constraints on triple oxygen isotope kinetics
Isotopic disequilibrium is not as well constrained as equilibrium, hindering interpretation of isotopic variations. Kinetic isotope effects, a subset of disequilibrium, are common in nature and have been assumed to be distinct from equilibrium and mass independent isotope effects based on underdeveloped criteria. Using basic physical principles, we provide needed mechanistic constraints on mass-de
Authors
Justin A. Hayles, Bryan Alan Killingsworth