Green River Research Articles

Movement ecology of imperilled fish in a novel ecosystem: River‐reservoir movements by razorback sucker and translocations to aid conservation

Abstract Reservoirs and associated river fragments are novel ecosystems not experienced by fishes in their evolutionary history, yet they are now commonplace across the globe. Understanding how fishes use these novel habitats is vital to conservation efforts in contemporary riverscapes. Movement patterns of the endangered razorback sucker (Xyrauchen texanus) synthesized from tagging efforts in the upper Colorado River basin, USA, illustrate the applications of tagging technology and data sharing by multiple agencies to better understand the spatial ecology of large river fishes. Tagging studies between 2014 and 2018 in Lake Powell and its two main tributary rivers, the Colorado (unfragmented) and San Juan (waterfall‐fragmented), were used to quantify movement of razorback sucker within this river–reservoir habitat complex. In addition, facilitated translocations of fish upstream of a waterfall barrier in the San Juan River were assessed in 2016–2017. Extensive movement of fish occurred within and across river and reservoir habitats. Of 722 fish captured in the Colorado River arm of Lake Powell, 36% of re‐encounters occurred upstream in the Colorado or Green rivers, or fish dispersed through the reservoir and were detected in the San Juan River arm. Fourteen fish moved more than 600 km. In the San Juan arm of the reservoir, 29% and 20% of fish in 2017 and 2018, respectively, had moved ~30–40 km upstream below the waterfall in the San Juan River within a year. In 2016–2017, 303 fish were translocated upstream of the waterfall into the San Juan River, but 80% were re‐encountered downstream of the waterfall within a year. Long‐distance movements by razorback sucker were common within and among rivers and reservoirs illustrating how large river fish, in general, might maintain population connectivity in highly altered ecosystems.

Evaluation of the integrated riparian ecosystem response to future flow regimes on semiarid rivers in Colorado, USA

Riparian ecosystems are shaped by interactions among streamflow, plants, and physical processes. Sustaining functioning riparian ecosystems in the face of climate change, growing human demands for water, and increasing water scarcity requires improved understanding of the sensitivity of riparian ecosystems to shifts in flow regimes and associated adaptive management strategies. We applied projected future flow regimes to an ecogeomorphic model of riparian and channel response to evaluate these interactions. We tested the hypothesis that components of the riparian ecosystem vary in their vulnerabilities to shifts in flow attributes and that changes in the representation of functional groups of plants result from interactions between ecological and physical drivers. Using the Yampa and Green Rivers in northwestern Colorado as our test system, we investigated ecogeomorphic response to (1) synthetic flow regimes representing continuous changes from baseline flows; and (2) future flow scenarios that incorporate changing climate, demand, and water-resource projects. For this region, we showed that riparian plant presence, composition, and cover are highly sensitive to the high flows that occur early in the growing season, but that shifts to low flows are also important, especially for determining the functional diversity of a riparian community. Future flow regimes are likely to induce vegetation encroachment on lower channel surfaces and to increase plant cover, which will be dominated by fewer functional groups. In particular, we predict a decrease in some mesic plants (shrubs and tall herbs) and an increase in presence and cover of late-seral, xeric shrubs, most of which are non-native species. Managing for high flows that occur early in the growing season must complement maintenance of adequate baseflows to maintain ecosystem functioning in the face of hydrologic alterations induced by climate change and human water demand.

Bird tracks from the Green River Formation (Eocene) of Utah: ichnotaxonomy, diversity, community structure and convergence

ABSTRACT Abundant well-preserved bird tracks from lacustrine Green River Formation (Eocene) deposits in Utah, are diverse and paleoecologically significant, but remain poorly known. Three of the four previously reported morphotypes (A-D) are named here for the first time with two representing new ichnotaxa. In order of increased footprint length (L) the ichnotaxa are: cf. Avipeda phoenix (L = 2.0 cm); Quadridigitus semimembranus ichnogen. et ichnosp. nov. (L = ~3.5 cm); Jindongornipes falkbuckleyi ichnosp. nov. (L ~ 8.0 cm); and previously named, web-footed Presbyornithiformipes feduccii (L = 9.5 cm). Collectively these avian ichnotaxa, associated invertebrate traces including ubiquitous nematode trails (Cochlichnus), and other rarer, small tetrapod tracks represent the “shorebird” ichnofacies or ichnocoenosis. However, the local track assemblages from the Uinta Basin do not correspond to the avian body fossil record from multiple Green River basins in the larger region. Thus, both records are essential for a cumulative picture. The Green River ichnotaxa are morphologically similar to those from lake basins in the Korean Cretaceous, and modern shorebird assemblages. As modern shorebirds are not known from Cretaceous or Eocene body fossils, the most plausible explanation is community convergence, among taxonomically disparate, but ecologically convergent trackmakers. Community convergence concepts help refine the ichnofacies paradigm.

Green River overlook, Island in the Sky District, Canyonlands National Park, southeastern Utah

The stream is still quiet, and we guide along through a strange, weird, grand region. The landscape everywhere, away from the river, is of rock—cliffs of rock, tables of rock, plateaus of rock, terraces of rock, crags of rock—ten thousand strangely carved forms; rocks everywhere, and no vegetation, no soil, no sand. In long, gentle curves the river winds about these rocks.
 These are the words Major John Wesley Powell used to describe what is called Stillwater Canyon along the Green River on July 17, 1869, on his way to the Grand Canyon during his famous journey exploring the canyons of the Colorado River and its tributaries (Powell, 1895). This same region is spectacularly displayedfrom the Green River Overlook in the Island in the Sky District of Canyonlands National Park. The exposed rocks consist of Early Permian- (299 million years ago [Ma]) through Early Jurassic-age (176 Ma) rock layers that were uplifted and subjected to massive erosion. Changes in the color, thickness, and composition ofthe rock layers and erosive work of running water and gravity (i.e., mass wasting) created the magnificent landscape seen at the overlook today. The primitive and remote Maze District of Canyonlands National Park is the area west of the Green River. Prominent features viewed in the Maze District from the Green River Overlook include Ekker Butte, Turks Head, Elaterite Butte, and the Orange Cliffs (figure 2). On a clear day, the 11,000-foot (3350 m), Henry
 Mountains, which are cored by volcanic remnants (laccoliths) can be seen to the southwest. The Green River Overlook is one of Utah’s most iconic views, often appearing on book covers, scenic calendars, and postcards, and therefore it is fitting as a geosite for its beauty and the exposures of rocks that so much impressed John Wesley Powell over 150 years ago.

Lithium isotope compositions of U.S. coals and source rocks: Potential tracer of hydrocarbons

Kerogen in organic-rich rocks contains trace amounts of lithium (Li) that has been overlooked as a contributor to the global Li geochemical cycle. This study examined a variety of coals where kerogen is concentrated (>50% organic carbon) and hydrocarbon source rocks of different ages, depositional environments and thermal maturity to determine their range of Li isotopic compositions (δ7Li‰) and factors that influence their compositions.Using Secondary Ion Mass Spectrometry (SIMS), we analyzed 22 coals and 4 hydrocarbon source rocks (Types I, II, III), to determine the δ7Li of kerogen in situ, without chemical isolation of phases that can alter their original isotopic compositions. The δ7Li values of the coals surveyed are distinctly isotopically light (<0‰) compared to most natural minerals and fluids. In immature coals, with a vitrinite reflectance in oil (VRo) of ≤0.5%, kerogen δ7Li values average –23.4 ± 1.1‰ and become heavier with increasing thermal grade to temperatures of gas generation (VRo ~1.3%). The linear correlation between δ7Li and VRo suggests that 6Li may be preferentially released to pore fluid from kerogen during thermal maturation. Notably, authigenic clays forming at diagenetic temperatures substitute Li from pore fluids into silicate layers, therefore, the Li isotopic composition of the clays may record fluid isotopic compositions influenced by organic-Li sources.NanoSIMS isotopic maps of the Lower Bakken Shale, and SIMS measurements of the Green River Shale show isotopically light Li associated with C-dominated areas, and heavier δ7Li with Si-dominated areas of the hydrocarbon source rocks. We conclude that kerogen is a source of isotopically light Li that contributes to fluids during thermal maturation and hydrocarbon generation. Kerogen may be a significant contributor of Li to pore fluids and its distinctly light Li isotopic composition relative to other terrestrial waters and minerals could provide a tracer of organic inputs to the global geochemical cycle.

Chemical Speciation and Stability of Uranium in Unconventional Shales: Impact of Hydraulic Fracture Fluid.

Uranium and other radionuclides are prominent in many unconventional oil/gas shales and is a potential contaminant in flowback/produced waters due to the large volumes/types of chemicals injected into the subsurface during stimulation. To understand the stability of U before and after stimulation, a geochemical study of U speciation was carried out on three shales (Marcellus, Green River, and Barnett). Two types of samples for each shale were subjected to sequential chemical extractions: unreacted and shale-reacted with a synthetic hydraulic fracture fluid. A significant proportion of the total U (20-57%) was released from these three shales after reaction with fracture fluid, indicating that U is readily leachable. The total U released exceeds labile water-soluble and exchangeable fractions in unreacted samples, indicating that fluids leach more recalcitrant phases in the shale. Radiographic analysis of unreacted Marcellus shale thin sections shows U associated with detrital quartz and the clay matrix in the shale. Detrital zircon and TiO2 identified by an electron microprobe could account for the hot spots. This study shows that significant proportions of U in three shales are mobile upon stimulation. In addition, the extent of mobilization of U depends on the U species in these rocks.

Experimental taphonomy of fish - role of elevated pressure, salinity and pH

Experiments are reported to reconstruct the taphonomic pathways of fish toward fossilisation. Acrylic glass autoclaves were designed that allow experiments to be carried out at elevated pressure up to 11 bar, corresponding to water depths of 110 m. Parameters controlled or monitored during decay reactions are pressure, salinity, proton activities (pH), electrochemical potentials (Eh), and bacterial populations. The most effective environmental parameters to delay or prevent putrefaction before a fish carcass is embedded in sediment are (1) a hydrostatic pressure in the water column high enough that a fish carcass may sink to the bottom sediment, (2) hypersaline conditions well above seawater salinity, and (3) a high pH to suppress the reproduction rate of bacteria. Anoxia, commonly assumed to be the key parameter for excellent preservation, is important in keeping the bottom sediment clear of scavengers but it does not seem to slow down or prevent putrefaction. We apply our results to the world-famous Konservat-Lagerstätten Eichstätt-Solnhofen, Green River, and Messel where fish are prominent fossils, and reconstruct from the sedimentary records the environmental conditions that may have promoted preservation. For Eichstätt-Solnhofen an essential factor may have been hypersaline conditions. Waters of the Green River lakes were at times highly alkaline and hypersaline because the lake stratigraphy includes horizons rich in sodium carbonate and halite. In the Messel lake sediments some fossiliferous horizons are rich in FeCO3 siderite, a mineral indicating highly reduced conditions and a high pH.

Insolation forcing of sub-lacustrine debris flows – Could monsoon intensification have played a role? Eocene lacustrine Green River Formation, Piceance Creek Basin, Colorado

Mudstone breccias deposited by debris flows in the lacustrine Green River Formation of the Piceance Creek Basin, Colorado, may not represent random and unpredictable events as previously thought. Spectral analysis of mudstone breccia beds in the Wolfridge Minerals John Savage #24-1 basin center core reveals a record of short eccentricity (94.58 kyr), obliquity (50.78 kyr and 39.26 kyr), and precession (21.85 kyr and 18.56 kyr). Of particular interest to this investigation are the records of eccentricity and precession, together which indicate that insolation forcing of monsoons occurred every ~18–21 kyr, and that every ~94 kyr, insolation maxima exceeded a threshold of 528 W/m2, resulting in more significant monsoon amplification. Strengthened monsoon activity would have led to an increase in precipitation and runoff delivered to the lake. This increase in inflow resulted in lake-level rise which, in turn, decreased basin slope stability and triggered periodic sub-lacustrine debris flows that deposited the mudstone breccias.

Lacustrine cyclicity in the early Eocene Green River Formation, Uinta Basin, Utah: Evidence from X-ray fluorescence core scanning

ABSTRACTThe Green River Formation preserves an extraordinary archive of terrestrial paleoclimate during the Early Eocene Climatic Optimum (EECO; ∼ 53–50 Ma), expressing multiple scales of sedimentary cyclicity previously interpreted to reflect annual to Milankovitch-scale forcing. Here we utilize X-ray fluorescence (XRF) core scanning and micro X-ray fluorescence (micro-XRF) scanning in combination with radioisotopic age data to evaluate a rock core record of laminated oil shale and carbonate mudstone from Utah's Uinta Basin, with the parallel objectives of elucidating the paleo-environmental significance of the sedimentary rhythms, testing a range of forcing hypotheses, and evaluating potential linkages between high- and low-frequency forcing. This new assessment reveals that the ∼ 100-μm-scale laminae—the most fundamental rhythm of the Green River Formation—are most strongly expressed by variations in abundance of iron and sulfur. We propose that these variations reflect changes in redox state, consistent with annual stratification of the lake. In contrast to previous studies, no support was found for ENSO or sunspot cycles. However, millimeter- to centimeter-scale rhythms—temporally constrained to the decadal to centennial scale—are strongly expressed as alternations in the abundance of silicate- versus carbonate-associated elements (e.g., Al and Si vs. Ca), suggesting changes in precipitation and sediment delivery to the paleo-lake. Variations also occur at the meter scale, defining an approximate 4 m cycle interpreted to reflect precession. We also identify punctuated intervals, associated principally with one phase of the proposed precession cycle, where Si disconnects from the silicate input. We propose an alternative authigenic or biogenic Si source for these intervals, which reflects periods of enhanced productivity. This result reveals how long-term astronomical forcings can influence short-term processes, yielding insight into decadal- to millennial-scale terrestrial climate change in the Eocene greenhouse earth.

Scale‐up of pore‐level relative permeability from micro‐ to macro‐scale

AbstractScaling up relative permeability curves of wetting and nonwetting phase of drainage and imbibition processes from pore scale to macro scale is a challenge. A new method for scaling up relative permeability from micro‐ to macro‐scale is proposed based on electrical analogy of multiphase fluid flow at pore scale. The method is validated against four synthetic porous media generated using homogeneous and heterogeneous grain size distributions, each of which were cut into eight sub‐segments. Single‐phase and two‐phase flow properties were calculated for the main blocks and the subsequent sub‐segments using random network modelling technique. Then, the subsegments were randomly distributed in space to reconstruct the main blocks and the proposed scale‐up method was employed to calculate the relative permeability curves of the reconstructed blocks. Results were compared to the ones obtained directly from the network model of the original blocks and show good agreement between the calculated and scaled‐up relative permeability curves of primary drainage and secondary imbibition. Furthermore, the model was tested on real media. Eight network models were extracted from pore size distribution of core samples obtained from the Green River basin located in the Mesaverde Formation. Flow properties obtained from the network models were validated against experimental data and good agreement was observed. These network models show a higher level of heterogeneity at micro‐scale. Then, the scale‐up methods were employed in order to reconstruct the macro‐scale sample and predict its properties. Scale‐up methods successfully predict the single‐phase and two‐phase flow properties of the sample.

PCA, CCA, and ANN Modeling of Climate and Land-Use Effects on Stream Water Quality of Karst Watershed in Upper Green River, Kentucky

AbstractClimate and land-use impacts on stream water quality in a karst watershed were studied to determine how they might be useful to model stream water quality parameter (SWQP) distribution from...

Learning the properties of Buton asphalt as an oil shale in Buton island to expand the knowledge of students about physics

Asphalt in Buton Island, Southeast Sulawesi, Indonesia, has a large reserve amount of around 650 million tons. In Buton, asphalt is only used for road construction, but this asphalt has characteristics that can be utilized as a substance to produce crude oil. The purposes of this research are to increase or expand the knowledge of educated participants about the characteristics and advantages of Buton asphalt and oil shale as community natural resources and to compare the density of each asphalt mining area namely Kabungka (winto mine), Lawele, and Sampolawa. It aims is to make Buton asphalt as a source of learning. The research method used is the literature study and experiment. The results of the study are that the characteristics of asphalt Buton approach the characteristics of oil shale in Green River, US. The density of Buton asphalt in each region is different. Conclusion of the research that asphalt/tar sand on Buton Island is categorized as a solid/semi-solid type hydrocarbon oil shale. The implementation of this study can be used for senior high school of class X student by visiting the asphalt mine to conduct simple experiments such as measuring the height of the asphalt cliff and determining the direction of the wind eye. Asphalt is used to measure its density. The experiment procedure is made in a module that will later be used by students.

Channel narrowing by inset floodplain formation of the lower Green River in the Canyonlands region, Utah

AbstractThe lower Green River episodically narrowed between the mid-1930s and present day through deposition of new floodplains within a wider channel that had been established and/or maintained during the early twentieth century pluvial period. Comparison of air photos spanning a 74-yr period (1940–2014) and covering a 61 km study area shows that the channel narrowed by 12% from 138 ± 3.4 m to 122 ± 2.1 m. Stratigraphic and sedimentologic analysis and tree ring dating of a floodplain trench corroborates the air photo analysis and suggests that the initial phase of floodplain formation began by the mid-1930s, approximately the same time that the flow regime decreased in total annual and peak annual flow. Tamarisk, a nonnative shrub, began to establish in the 1930s as well. Narrowing from the 1940s to the mid-1980s was insignificant, because floodplain formation was approximately matched by bank erosion. Air photo analysis demonstrates that the most significant episode of narrowing was underway by the late 1980s, and analysis of the trench shows that floodplain formation had begun in the mid-1980s during a multi-year period of low peak annual flow. Air photo analysis shows that mean channel width decreased by ∼7% between 1993 and 2009. A new phase of narrowing may have begun in 2003, based on evidence in the trench. Comparison of field surveys made in 1998 and 2015 in an 8.5 km reach near Fort Bottom suggests that narrowing continues and demonstrates that new floodplain formation has been a very small proportion of the total annual fine sediment flux of the Green River. Vertical accretion of new floodplains near Fort Bottom averaged 2.4 m between 1998 and 2015 but only accounted for ∼1.5% of the estimated fine sediment flux during that period. Flood control by Flaming Gorge Dam after 1962 significantly influenced flow regime, reducing the magnitude of the annual snowmelt flood and increasing the magnitude of base flows. Though narrowing was initiated by changes in flow regime, native and nonnative riparian vegetation promoted floodplain formation and channel narrowing especially through establishment on channel bars and incipient floodplains during years of small annual floods.

Organic chemical structure relationships to maturity and stability in shales

The systematic understanding of organic matter chemical structure-thermal stability relationships is central to resource outcomes in sedimentary basins. This study integrates molecular spectroscopy (solid-state 13C NMR) and step-wise isothermal analysis (isoTGA) in elucidating key structure-maturity-stability relationships in shales containing type I and II kerogens (Green River and Eagle Ford Formations, respectively) that were subjected to simulated maturation via hydrous pyrolysis. Hydrous pyrolysis temperatures ranged from 250 to 400 °C – the window for immature to oil generation in the catagenic process (corresponding to Easy %Ro 0.36 to 1.07). Specifically, mole fraction aromatic C (fa) revealed strong correlations with pyrolysis temperature across both kerogen types, increasing 14.8 to 44.9 mol% and 19.7 to 75.2 mol% in the Green River and Eagle Ford samples, respectively. Aromatic bridgehead C (faB), a measure of aromatic ring condensation, showed limited predictive variation with maturity. The increase in aromatization/condensation was accompanied by increased pyrolytic cracking of alkyl C (fal), which decreased from 66.2 to 42.9 mol% in the Green River and 56.1 to 12.2 mol% in the Eagle Ford kerogen. Our 13C NMR analyses of the kerogens revealed empirical relationships that can be used for predicting pyrolysis temperature and maturity (Easy %Ro) based on the major organic structural properties of kerogen. Step-wise, isothermal thermogravimetric analyses allowed for the estimation of kinetic parameters associated with catagenesis: activation energy (Ea) and frequency factor (A). Thermal decomposition of kerogen was revealed to be a two-stage process, and increasing maturity generally resulted in an increase of thermal stability/activation energy. First-stage activation energies (Ea1) ranged 64.0 to 44.7 kJ mol−1, while second-stage activation energies (Ea2) ranged 151.4 to 198.9 kJ mol−1 with increasing maturity in the Green River samples. Similarly, Ea1 and Ea2 of the Eagle Ford ranged 13.1 to 46.0 kJ mol−1 and 208.0 to 286.2 kJ mol−1, respectively. The quantitative determination of covariation in organic structure and thermal stability of kerogen with increasing maturity can be useful in further parameterizing Basin and Petroleum System Models (BPSMs). Furthermore, these results can support the development of computational models of petroleum generation and further facilitate the experimentally-driven understanding of the interplay between organic structure and thermal stability in petroleum systems.

Comparison of vector competence of Aedes vexans Green River and Culex pipiens biotype pipiens for West Nile virus lineages 1 and 2.

West Nile virus (WNV), a zoonotic arbovirus, has recently established an autochthonous transmission cycle in Germany. In dead-end hosts like humans and horses the WNV infection may cause severe symptoms in the central nervous system. In nature, WNV is maintained in an enzootic transmission cycle between birds and ornithophilic mosquitoes. Bridge vector species, such as members of the Culex pipiens complex and Aedes spp., also widely distributed in Germany, might transmit WNV to other vertebrate host species. This study determined and compared the vector competence of field-collected northern-German Cx. pipiens biotype pipiens and laboratory-reared Ae. vexans Green River (GR) for WNV lineage 1 (strain: Magpie/Italy/203204) and WNV lineage 2 (strain: "Austria") under temperatures typical for northern Germany in spring/summer and autumn. For assessment of vector competence, 7- to 14-day-old female mosquitoes were offered a WNV containing blood meal via Hemotek membrane feeding system or cotton-stick feeding. After incubation at 18°C respectively 24°C for 14days engorged female mosquitoes were salivated and dissected for determination of infection, dissemination and transmission rates by reverse transcriptase quantitative real-time PCR (RT-qPCR). Both Ae. vexans GR and Cx. pipiens biotype pipiens were infected with both tested WNV strains and tested 14days post-inoculation. Disseminated infections were detected only in Ae. vexans GR incubated at 18°C and in Cx. pipiens pipiens incubated at 24°C after infection with WNV lineage 1. Transmission of WNV lineage 1 was detected in Cx. pipiens pipiens incubated at 24°C. These results indicate that Cx. pipiens pipiens from Northern Germany may be involved in the transmission of WNV, also to dead-end hosts like humans and horses.

The Oldest Representative of the Rove Beetle Tribe Pinophilini (Coleoptera: Staphylinidae: Paederinae), from Upper Cretaceous Burmese Amber.

The recently reviewed subtribe Procirrina comprises eight extant genera with a predominately (sub)tropical distribution. Previous phylogenies consistently recover the tribe Pinophilini of the subfamily Paederinae monophyletic. No fossils of the tribe have been described, although compression fossils are known from the Cenozoic Green River Formation (50.3–46.2 Ma) as well as inclusions from the Miocene Dominican (20.43–13.65 Ma) and Mexican (20–15 Ma) ambers. Here we describe †Cretoprocirrus trichotos Jenkins Shaw and Żyła gen. et sp. n., the oldest fossil representative of the tribe Pinophilini, from Upper Cretaceous Burmese amber (ca. 99 Ma). Phylogenetic analyses of morphological data allow its unambiguous placement in the subtribe Procirrina. †Cretoprocirrus trichotos is the second genus of Paederinae described from Burmese amber and provides an important insight into the evolution of the subfamily.

Uncertainty Quantification of an Explicitly Coupled Multiphysics Simulation of In-Situ Pyrolysis by Radio Frequency Heating in Oil Shale

SummaryIn-situ pyrolysis provides an enhanced oil recovery (EOR) technique for exploiting oil and gas from oil shale by converting in-place solid kerogen into liquid oil and gas. Radio-frequency (RF) heating of the in-place oil shale has previously been proposed as a method by which the electromagnetic energy gets converted to thermal energy, thereby heating in-situ kerogen so that it converts to oil and gas. In order to numerically model the RF heating of the in-situ oil shale, a novel explicitly coupled thermal, phase field, mechanical, and electromagnetic (TPME) framework is devised using the finite element method in a 2D domain. Contemporaneous efforts in the commercial development of oil shale by in-situ pyrolysis have largely focused on pilot methodologies intended to validate specific corporate or esoteric EOR strategies. This work focuses on addressing efficient epistemic uncertainty quantification (UQ) of select thermal, oil shale distribution, electromagnetic, and mechanical characteristics of oil shale in the RF heating process, comparing a spectral methodology to a Monte Carlo (MC) simulation for validation. Attempts were made to parameterize the stochastic simulation models using the characteristic properties of Green River oil shale. The geologic environment being investigated is devised as a kerogen-poor under- and overburden separated by a layer of heterogeneous yet kerogen-rich oil shale in a target formation. The objective of this work is the quantification of plausible oil shale conversion using TPME simulation under parametric uncertainty; this, while considering a referenced conversion timeline of 1.0 × 107 seconds. Nonintrusive polynomial chaos (NIPC) and MC simulation were used to evaluate complex stochastically driven TPME simulations of RF heating. The least angle regression (LAR) method was specifically used to determine a sparse set of polynomial chaos coefficients leading to the determination of summary statistics that describe the TPME results. Given the existing broad use of MC simulation methods for UQ in the oil and gas industry, the combined LAR and NIPC is suggested to provide a distinguishable performance improvement to UQ compared to MC methods.

&lt;p&gt;&lt;strong&gt;The second genus of the extinct dragonfly family Urolibellulidae from the Eocene Green River Formation (Odonata, Anisoptera: Cavilabiata)&lt;/strong&gt;&lt;/p&gt;

If the oldest record of the anisopteran ‘libelluloid’ group Anauriculida Bechly, 1996 goes to the Cretaceous (Fleck et al., 1999; Kohli et al., 2016), its extant families are scarce or even absent before the Eocene. Nevertheless, the Anauriculida were already rather diverse during Eocene with a Libellulidae in the earliest Eocene (Fleck et al., 2000), and the extinct monotypic family Urolibellulidae in the middle Eocene Green River Formation (Zeiri et al., 2015). Crown Libellulidae become more and more frequent and diverse during Oligocene, and even dominate the dragonfly fauna in some outcrops (Céreste, Rott, Aix-en-Provence, Bes-Konak) (Nel &amp; Paicheler, 1993). Thus any discovery in the Paleocene–Eocene of a new fossil related to these families is welcome. Here we describe a complete hindwing of this kind from the Green River Formation in Colorado.

Modeling the Behavior of Organic Kerogen in the Proximity of Calcite Mineral by Molecular Dynamics Simulations

Green River oil shale, a sedimentary rock, and an agglomerate of organic kerogen and minerals is the largest reserve of shale oil in the world. The production of shale oil requires the extraction of kerogen from the minerals. Our prior experiments have shown that the kerogen in the shale lies in pores of tens of nanometers and is influenced by molecular interactions with the minerals. Calcite (CaCO3) is one of the predominant minerals present in Green River oil shale, and thus finding its interaction with kerogen is important. Molecular dynamics simulation is utilized in the present study to investigate the interactions between calcite mineral and the Green River kerogen which is Type I kerogen. The CHARMm force field parameters of calcite are derived from available parameters that are based on a rigid ion model. The expanded model of calcite is merged on top of the 12-unit kerogen model to study their interactions at NTP (Normal Temperature and Pressure) conditions. All the hydrocarbon fragments of kerog...

Copper Isotopic Analysis in Geological and Biological Reference Materials by MC‐ICP‐MS

The characterisation of relative copper isotope amount ratios (δ65Cu) helps constrain a variety of geochemical processes occurring in the geosphere, biosphere and hydrosphere. The accurate and precise determination of δ65Cu in matrix reference materials is crucial in the effort to validate measurement methods. With the goal of expanding the number and variety of available geological and biological materials, we have characterised the δ65Cu values of ten reference materials by MC‐ICP‐MS using C‐SSBIN model for mass bias correction. SGR‐1b (Green River shale), DOLT‐5 (dogfish liver), DORM‐4 (fish protein), TORT‐3 (lobster hepatopancreas), MESS‐4 (marine sediment) and PACS‐3 (marine sediment) have for the first time been characterised for δ65Cu. Additionally, four reference materials (with published δ65Cu values) have been characterised: BHVO‐1 (Hawaiian basalt), BIR‐1 (Icelandic basalt), W‐2a (diabase) and Seronorm™ Trace Elements Serum L‐1 (human serum). The reference materials measured in this study possess complex and varied matrices with copper mass fractions ranging from 1.2 µg g−1 to 497 µg g−1 and δ65Cu values ranging from −0.20‰ to 0.52‰ with a mean expanded uncertainty of ± 0.07‰ (U, k = 2), covering much of the natural copper isotope variability observed in the environment.