Rock Springs Research Articles

Classifying basin‐scale stratigraphic geometries from subsurface formation tops with machine learning

AbstractPresented here is a transfer‐learning model for classifying basin‐scale stratigraphic geometries from subsurface formation tops. Support vector, decision trees, random forests, AdaBoost and K‐nearest neighbour classification models are evaluated to support this challenge. Each model is trained on labelled synthetic stratigraphic geometry data generated in Python using observable geological principles and concepts. Accuracy is measured using a weighted Jaccard similarity coefficient score, and certainty of each prediction is quantified using margin sampling. The random forest classifier has the highest initial accuracy, and the optimal hyperparameters for the model that yield 88.4% accuracy and 72.8% mean certainty via five‐fold cross‐validation and active learning are documented on a real‐world subsurface dataset. The random forest classifier with optimised hyperparameters is then used to make predictions on the real‐world subsurface formation tops dataset. The dataset consists of formation tops for the Upper Cretaceous and Palaeocene strata of the Eastern Greater Green River Basin in south‐central Wyoming. Results from model predictions include an area of truncation in the Lance Formation across the basin, and an area of onlap and truncation on the nose of the Rock Springs Uplift that previous studies in the region corroborate. It is believed that this model is most useful for guided interpretation, and identifying regions that warrant further inquiry by domain experts.

Performance of Sweetpotato Varieties Grown Using Black Plastic Mulch in Pennsylvania

Sweetpotato (Ipomoea batatas) production in Pennsylvania and the northeastern United States has been increasing steadily. The performance of eight commercially available sweetpotato varieties and two unreleased accessions grown on raised beds and covered with black plastic mulch in Pennsylvania was evaluated. All varieties and accessions were evaluated in 2 successive years (2018 and 2019) at Rock Springs, PA. There were statistically significant differences in total marketable yield (TMY), but not in all yield components in both years. ‘Orleans’, ‘Beauregard’, ‘Averre’, and ‘Covington’ consistently produced high marketable yields and suitable U.S No.1 grade storage roots. ‘Bonita’ (tan skin/white flesh) and ‘Carolina Ruby’ [red skin/orange flesh (OF)] produced consistent yields in both years (range, 330–430 bushels/acre; 50-lb bushel). NC413 [purple skin (PS)/purple flesh (PF)] produced the lowest yield in 2018 and was discarded for future trials. In 2019, NCP13-0030 (PS/PF) produced good yields and shapes comparable to OF varieties. Overall total yields (TYs) measured in this study compared satisfactorily with average nationwide yields, with several varieties producing more than 500 bushels/acre.

In Memoriam: Keith Quentin Hayes II (1965–2020)

The mineral community lost a much‐too‐young member on 5 June of this year. After a valiant battle with cancer, Keith Quentin Hayes II, at the age of fifty‐five, passed at his home in Rock Springs, ...

Assessment of relationship between post-injection plume migration and leakage risks at geologic CO2 storage sites

We performed a numerical modeling study focused on the relationship between post-injection plume migration and leakage risks at geologic CO2 storage sites. We use the model for Rock Springs Uplift in southwestern Wyoming as our hypothetical case study. We performed multiple sets of reservoir simulations, each with 29 equi-probable realizations of reservoir permeability heterogeneity, simulating different injection scenarios. Three different CO2 injection rates and an open and compartmentalized reservoir are evaluated. We applied newly developed moment-based plume mobility metrics to characterize migration and evolution of injected CO2 plume. We applied the integrated assessment model developed by the National Risk Assessment Partnership (NRAP-IAM-CS) using the results of reservoir simulations of CO2 and overpressure to quantify potential CO2 and brine leakage through wells and resulting groundwater aquifer impacts. The plume mobility metrics provide detailed analyses of the effect of reservoir permeability heterogeneity, CO2 injection rate, and compartmentalization on CO2 plume and overpressure areas, velocities, and spreading. Based on leakage risk assessment our results indicate that lack of injected CO2 plume stability (or non-zero plume mobility) may not directly imply groundwater aquifer endangerment and the leakage risks are dependent on multiple factors beyond CO2 plume stability including presence of wells and their locations and types.

Temporal Variation in Genetic Composition of Migratory Helicoverpa Zea in Peripheral Populations.

Migrant populations of Helicoverpa zea (Boddie) captured during 2002, 2005, 2016, and 2018 from Landisville and Rock Springs in Pennsylvania, USA were genotyped using 85 single nucleotide polymorphism (SNP) markers. Samples (n = 702) genotyped were divided into 16 putative populations based on collection time and site. Fixation indices (F-statistics), analysis of molecular variance, and discriminant analysis of principal components were used to examine within and among population genetic variation. The observed and expected heterozygosity in putative populations ranged from 0.317–0.418 and 0.320–0.359, respectively. Broad range of FST (0.0–0.2742) and FIS (0.0–0.2330) values indicated different genotype frequencies between and within the populations, respectively. High genetic diversity within and low genetic differentiation between populations was found in 2002 and 2005. Interestingly, high genetic differentiation between populations from two collection sites observed in 2018 populations was not evident in within-site comparisons of putative populations collected on different dates during the season. The shift of H. zea population genetic makeup in 2018 may be influenced by multiple biotic and abiotic factors including tropical storms. Continued assessment of these peripheral populations of H. zea will be needed to assess the impacts of genetic changes on pest control and resistance management tactics.

Statistical rock physics inversion of elastic and electrical properties for CO2 sequestration studies

SUMMARY We present a statistical rock physics inversion of the elastic and electrical properties to estimate the petrophysical properties and quantify the associated uncertainty. The inversion method combines statistical rock physics modeling with Bayesian inverse theory. The model variables of interest are porosity and fluid saturations. The rock physics model includes the elastic and electrical components and can be applied to the results of seismic and electromagnetic inversion. To describe the non-Gaussian behaviour of the model properties, we adopt non-parametric probability density functions to sample multimodal and skewed distributions of the model variables. Different from machine learning approach, the proposed method is not completely data-driven but is based on a statistical rock physics model to link the model parameters to the data. The proposed method provides pointwise posterior distributions of the porosity and CO2 saturation along with the most-likely models and the associated uncertainty. The method is validated using synthetic and real data acquired for CO2 sequestration studies in different formations: the Rock Springs Uplift in Southwestern Wyoming and the Johansen formation in the North Sea, offshore Norway. The proposed approach is validated under different noise conditions and compared to traditional parametric approaches based on Gaussian assumptions. The results show that the proposed method provides an accurate inversion framework where instead of fitting the relationship between the model and the data, we account for the uncertainty in the rock physics model.

In‐row subsoiling benefits maize yield on soil with a shallow fragipan

AbstractPast research showed no yield improvement with subsoiling compared with no‐tillage on well‐drained soils in Pennsylvania. However, subsoiling may benefit crop yields on soils with a compacted subsoil, such as a fragipan. Fragipan soils cover 30% of the land surface of Pennsylvania and 27 million acres in the United States. This study was conducted to determine whether subsoiling an Andover loam soil (fine‐loamy, mixed, active, mesic Typic Fragiaquult) with a fragipan starting at 19 inches and a seasonally high water table would result in maize (Zea mays L.) yield improvements compared with no‐till. The research took place at Rock Springs, central Pennsylvania, from 2012 to 2014. Soil was subsoiled every spring to a 17‐inch depth with a straight‐shank subsoiler with straight tips and fluted coulters behind it. Approximately 80% of the soil surface remained undisturbed, guaranteeing soil erosion protection by crop residue and soil health maintenance. Penetration resistance was reduced by subsoiling to 14 inches the first year, and penetration resistance was still significantly lower than under no‐tillage 1 year later at 7 to 13 inches deep. On average, subsoiling increased maize yields by 11%. This research shows that subsoiling with reduced surface disturbance can increase maize yields on soils with a shallow fragipan while maintaining the benefits of conservation tillage for soil health.

Reducing uncertainty in geologic CO2 sequestration risk assessment by assimilating monitoring data

Geologic CO2 sequestration sites usually have large uncertainty in geological properties, such as uncertainty in permeability and porosity fields. Geological uncertainty leads to significant uncertainty in predicted risk metrics such as CO2 plume extent, CO2/brine leakage rates through wellbores, and impacts to drinking water quality in groundwater aquifers due to CO2/brine leakage, all of which will impact the approach for post injection site care (PISC). Pre-injection risk assessment can be used to quantify the amount of uncertainty in different predicted risk metrics. However, it cannot account for the potential value of monitoring data (e.g., CO2 saturation and pressure measurements) acquired during the operation of CO2 storage. In this study, we demonstrate how uncertainty in predicted risks can be reduced by performing monitoring data assimilation. An ensemble of geological reservoir models, constrained by direct measurements (such as permeability estimates from exploratory wells), are generated by geostatistical conditional simulation. As the monitoring data from the storage site become available, they are assimilated into models using a recently developed data assimilation method, ES-MDA with geometric inflation factors (ES-MDA-GEO). The reservoir models, calibrated through multiple data assimilation iterations, are used to predict future risks and reduction in their uncertainties. The proposed approach for the quantification of uncertainty reduction in risk assessment is demonstrated with two examples: a generalized 3D synthetic case and a synthetic field case based on the Rock Springs Uplift site in southwestern Wyoming.

Systematics and paleobiology of Chiromyoides (Mammalia, Plesiadapidae) from the upper Paleocene of western North America and western Europe

ABSTRACT Relatively large new samples of the rare plesiadapid mammal Chiromyoides are reported from upper Paleocene rocks exposed along the eastern flank of the Rock Springs Uplift and the adjacent Washakie Basin in southwestern Wyoming. These specimens form the basis for the new upper Tiffanian species Chiromyoides kesiwah and enhance our knowledge of the anatomy of early Clarkforkian C. gingerichi. Multiple previously unreported or unrecognized specimens of Chiromyoides are also described from upper Paleocene faunas in Texas, Colorado, and Wyoming, enabling a new phylogenetic analysis of all known species of Chiromyoides and selected other plesiadapids and outgroup taxa. The phylogeny of Chiromyoides appears to have been more complicated than previously described, partly because the genus was more speciose than previously appreciated. European C. campanicus and C. mauberti are sister taxa that are deeply nested within an otherwise North American radiation of Chiromyoides, suggesting that Chiromyoides originated in North America before dispersing to Europe in the latter part of the Tiffanian. Most of the derived anatomical features that distinguish Chiromyoides from closely related plesiadapids indicate that it was yet another occupant of the lucrative ‘mammalian woodpecker’ niche, alongside the extant Malagasy lemur Daubentonia, the extant phalangeroid marsupial Dactylopsila, early Cenozoic placental Apatemyidae, and possibly the middle Cenozoic metatherian Yalkaparidon. http://zoobank.org/urn:lsid:zoobank.org:pub:32D24F6B-7429-4927-8BB8-C2766FFB568A

Omission and Imagery in Hemingway’s “Up in Michigan,” Carver’s “Chef’s House,” Ford’s “Rock Springs,” and Mason’s “Residents and Transients”

Ernest Hemingway’s minimalist style, which is based on his “Theory of Omission,” has exerted a considerable influence on generations of writers. This article provides additional evidence with respect to his narrative influence on the short fiction of the leading figures of literary minimalism. To fulfil this primary aim, a comparative and an analytical study is carried out using Wolfgang Iser’s reception theory. This has been deployed in order to demonstrate that the narrators of Raymond Carver’s “Chef’s House,” Richard Ford’s “Rock Springs,” and Bobbie Ann Mason’s “Residents and Transients” employ the techniques of omission and imagery to affect the readers’ imagination and engage them in the construction of the story’s meaning .More interesting, they make them feel more than they understand the emotional state of the characters, which is left beneath the surface of things, as does Hemingway in his story “Up in Michigan.”

Shallow‐water deltaic clinoforms and process regime

AbstractUtilizing two outcrop data sets with dip direction exposures of shallow‐water (tens of meters) deltaic clinoforms, this paper quantifies sedimentary facies proportions and clinoform lengths and gradients, and links process regimes to delta clinoform dimensions. Both data sets are from foreland basins, the Cretaceous Chimney Rock Sandstone of the Rock Springs Formation from the US Western Interior, and the Eocene Brogniartfjellet Clinoform Complex 8 of the Battfjellet Formation from the Central Basin of Spitsbergen. Sedimentary facies indicate presence of both river‐ and wave‐dominated clinothems in each data set. Facies characteristics and distribution implies that river‐dominated clinothem progradation was primarily driven by deposition from weak hyperpycnal flow turbidity currents across the clinoforms, and minor slumps. Wave‐dominated clinothems were constructed by wave processes rather than alongshore currents, and are also progradational subaerial clinoforms, with one exception, where the formation of a compound subaqueous clinoform set indicates erosion and sediment bypass above the wave base. Sediment distribution and lithological heterogeneity in the river‐dominated clinothems is controlled by individual hyperpycnal flow events or mouth‐bar collapse events, and thus by self‐organization and minimal reworking that results in a heterogeneity that is difficult to predict (high entropy). The efficient reworking of river‐derived sediments in wave‐dominated clinothems results in predictable lithological sediment partitioning (low entropy). Clinoform dimension analyses show that although of similar sediment caliber, river‐dominated clinoforms in both data sets are on average 3–4 times steeper and 3–4 times shorter than the wave‐dominated clinoforms, with mean gradients of ca 4 degrees and ca 1 degree, respectively, and mean lengths of 150–230 m and 640–760 m. These results require corroboration from additional data sets, but do suggest that river‐ and wave‐dominated delta clinoforms are likely to have distinct downdip extents (lengths) and gradients for given clinoform heights. Clinoform shape can thus be a method for differentiating ancient river‐ vs. wave‐dominated deltaic clinoforms, in addition to their sedimentary facies, biogenic features and sandstone maturity, and helpful when incorporated into reservoir models.

Experimental investigation of the effect of compliant pores on reservoir rocks under hydrostatic and triaxial compression stress states

The presence of compliant pores in rocks is important for understanding the stress–strain behaviors under different stress conditions. This paper describes findings on the effect of compliant pores on the mechanical behavior of a reservoir sandstone under hydrostatic and triaxial compression. Laboratory experiments were conducted at reservoir temperature on Weber Sandstone samples from the Rock Springs Uplift, Wyoming. Each experiment was conducted at three sequential stages: (stage 1) increase in the confining pressure while maintaining the pore pressure, (stage 2) increase in the pore pressure while maintaining the confining pressure, and (stage 3) application of the deviatoric load to failure. The nonlinear pore pressure – volumetric strain relationship governed by compliant pores under low confining pressure changes to a linear behavior governed by stiff pores under higher confining pressure. The estimated compressibilities of the matrix material in sandstone samples are close to the typical compressibility of quartz. Because of the change in pore structures during stage 1 and stage 2 loadings, the estimated bulk compressibilities of the sandstone sample under the lowest confining pressure decrease with increasing differential pressure. The increase in crack initiation stress is limited with increasing differential pressure because of similar total crack length governed by initial compliant porosity in sandstone samples.

Investigating the effect of burial histories on the clumped isotope thermometer: An example from the Green River and Washakie Basins, Wyoming

Abstract The Δ47 clumped isotope thermometer has been applied to multiple studies aimed at reconstructing the paleoelevation and paleoclimate of sedimentary basins and paleosol sequences. Ideally, this technique directly preserves the temperature of carbonate formation, avoiding any speculation on the composition of surface water from which the carbonate precipitated. Recently, however, concerns about post-depositional alteration of the Δ47 isotope signature from the effects of burial and/or diagenetic alteration have arisen, potentially complicating the application of the Δ47 clumped isotope thermometer for determining paleo-surface temperatures. Here we investigate the effect of burial history on mass-47 clumped isotope. To this purpose we collected samples, from the surface and from drill cores, in two different areas of the Greater Green River basin: the Washakie Basin near Rock Springs, Wyoming and the Green River Basin near Pinedale, Wyoming. Both basins are filled with a thick sequence of Eocene lacustrine strata and the thermal histories of both basins are well documented from petroleum prospecting studies. Clumped isotope Δ47 compositions were measured from lacustrine micritic limestones with a range of peak burial depths from 1 to 6.5 km. For samples from the Washakie Basin that did not experience burial depths exceeding ∼2000 meters, the measured Δ47 values vary from 0.623‰ to 0.684‰, yielding carbonate formation temperatures consistent with previously hypothesized Paleocene-Eocene surface temperatures. In contrast, samples from the Green River Basin, collected from greater burial depths, demonstrate significantly lower Δ47 values (higher temperatures). The consistency of δ18O values and lack of CL evidence for recrystallization suggest closed-system resetting of the clumped isotope thermometer by either partial solid-state re-ordering or carbonate reprecipitation during burial. The Δ47 values of the deeply buried samples have been compared to values derived from recrystallization and temperature history reordering models (THRMs). Both recrystallization and reordering models are successful at predicting Δ47 reordering at burial temperatures >100 °C. These observations, from samples collected from a basin with a remarkably well-constrained thermal history and geothermal gradient, highlight the challenges in elucidating burial histories or diagenetic processes solely from clumped isotopic compositions.

The effects of multiple covers with condensation and optical degradation of a polyethylene windscreen on the performance of a sky cooling system

ABSTRACTThis study evaluates the performance of a heat-pipe-augmented sky radiator system modelled using MATLAB. It was developed to simulate thermal networks with the following nodes: polyethylene cover(s), radiator plate with selective surface, heat pipe condenser end, heat pipe evaporator end, thermal storage fluid, fluid container wall, and room. Applying a windscreen of polyethylene that is mostly transparent to long-wave radiation, a drawback is its susceptibility to optical property degradation. Sky fractions of 100% were possible in cities with small cooling loads (Rock Springs, Seattle, San Diego and Denver). Sky fractions of over 50% were achieved in New Orleans and Houston and over 40% in Miami. A second study examined the degradation of polyethylene cover material. Louisville and two challenging climates (Miami and New Orleans) were simulated. In the Louisville, Miami and New Orleans climate, performance was reduced by 2.7, 14.1 and 9.0%, respectively, due to degradation of the cover’s material.

Low‐Field Nuclear Magnetic Resonance Characterization of Carbonate and Sandstone Reservoirs From Rock Spring Uplift of Wyoming

AbstractLaboratory measurements including gas (N2) porosity and permeability, time‐domain nuclear magnetic resonance, thin section, and scanning electron microscopy analysis were conducted to obtain petrographical and petrophysical descriptions of the Weber Sandstone and Madison Limestone at the Rock Spring Uplift, a potential carbon dioxide storage site in Southwestern Wyoming. The relationships between pore structures, such as pore geometry, pore‐size distribution, pore network, and porosity/permeability are investigated. First, using thin sections combined with scanning electron microscopy for pore structures description, all samples are described in detail from the geological, petrographysical, and diagenetic viewpoint. Results show that within the Madison Limestone, pore types include intercrystalline, vuggy, moldic, or mixed (combination of all other pore types). Both moldic and vuggy pore types are associated with samples of high porosity and permeability. Nuclear magnetic resonance relaxation time distributions show either bimodal or multimodal distributions. Large relaxation time components are associated with samples with large pores, whereas small components are dominated by small pores. The T2 geometric mean correlates well with gas permeability. Additionally, short‐time diffusion coefficients (D) were measured by pulsed field gradient method using a series of gradient strengths. We found that diffusion coefficient distributions correlate with the corresponding T2 distributions for macropores. By comparing the dominant peak position of T2 distributions and their corresponding diffusion coefficient distributions, we predicted the surface relaxivity of different rock types. We found that surface relaxivities of Weber Sandstone samples can be well predicted, while for Madison Limestone samples, surface relaxivities are overestimated due to diffusive pore coupling effect.

Subsurface Reinterpretation of Ordovician and Devonian Strata in Southwest Wyoming with Implications for Upwarping Across the Transcontinental Arch

A new interpretation of the subsurface geometries of the Ordovician Bighorn Dolomite and overlying Devonian strata across southwestern Wyoming arises from revising the stratigraphy in a core from the Mountain Fuel Supply UPRR #11–19–104–4 well drilled on the crest of the Rock Springs Uplift in 1962. One of only a few wells to penetrate all or part of the Lower Paleozoic succession in the subsurface of southwestern Wyoming, the well was almost continuously cored through the Devonian–Cambrian succession. From a reinterpretation of the stratigraphy in the core, 22 ft of Bighorn Dolomite is recognized based on the characteristic Thalassinoides bioturbation fabric in skeletal dolowackestone typical of Late Ordovician subtidal carbonate facies ranging from Nevada to Greenland along the western margin of the Great American Carbonate Bank. This lithology is in complete contrast with the alternating dolomitic flat-pebble conglomerate and dolomudstone of the underlying Cambrian Gallatin Limestone and the cyclical units of brecciated anhydritic dolomudstone and quartzose sandstone of the overlying Devonian Lower Member of the Jefferson Formation. Stratigraphic re-interpretation yields insights regarding Ordovician–Devonian stratal geometries across southwestern Wyoming. More widespread than previously portrayed, the Bighorn Dolomite pinches out on the eastern flank of the Rock Springs Uplift. Similar to past interpretations, Devonian strata pinch out east of the Rock Springs Uplift at Table Rock Field. A true-geometry multi-datumed stratigraphic cross section yields insights not obtainable by mapping. Regionally, top truncation of stratigraphic units below the base-Madison Limestone unconformity normally progresses stratigraphically deeper eastward. However, in southwestern Wyoming, the Devonian Lower Member of the Jefferson Formation overlaps the older Bighorn Dolomite by marked onlap across the Rock Springs Uplift and then pinches out by top truncation/onlap near Table Rock Field, forming an “abnormal” overlap relationship along the northern margin of the Transcontinental Arch. The underlying Bighorn Dolomite shows little to no onlap onto the underlying Cambrian section, but is markedly top truncated below the Lower Member of the Jefferson Formation. Comparing proportions of onlap versus top truncation for the two formations constrains the timing of two successive upwarping episodes along the northern margin of the Transcontinental Arch across southwestern Wyoming. The first is arguably Middle Devonian, and the second spans the Devonian–Mississippian boundary. Two subtle and different angular unconformities created by these two episodes imply a persistent fold or tilt axis that sequentially was reactivated along the northern margin of the Transcontinental Arch in southwestern Wyoming.

“Reckless People”: Negotiations of identity in Richard Ford’s Rock Springs

ABSTRACTIn an early profile of Richard Ford, Bruce Weber referred to the “uncommon characters” in Rock Springs; a few years later, Elizabeth Hardwick characterized them as “reckless people,” while Jeffrey J. Folks has quite usefully offered “postmodern cowboys.” This article revisits Rock Springs to establish whether there is indeed something unique or distinctive or even generalizable about the characters, noting some of the pronouncements on the concept of character by Ford and his famous protagonist, Frank Bascombe. The article then explores Ford’s canny witness to some of the ways in which certain characters fudge their life narratives or “narrative identities” (Ricoeur) in order to render them more acceptable to themselves and to others. This process, which involves accommodating cognitive dissonance or bad faith (Sartre), is what sanctions and thus effectively enables their reckless behavior.

Magnetotelluric investigation of the Colorado front range thrust fault between Castle Rock and Colorado Springs, Colorado

Magnetotelluric investigation of the Colorado front range thrust fault between Castle Rock and Colorado Springs, Colorado

Oral Antibiotic Use and Risk of Colorectal Cancer in the United Kingdom, 1989-2012: A Matched Case-Control Study

Background: Microbiome dysbiosis predisposes to colorectal cancer (CRC), but a population-based study of antibiotic exposure and risk patterns is lacking. In this study, oral antibiotic use on CRC incidence was assessed. Methods: A matched case-control study (incident CRC cases and up to 5 matched controls) was performed using the Clinical Practice Research Datalink (CPRD; January 1, 1989 to December 31, 2012). Conditional logistic regression was used to assess CRC association with oral antibiotic use, adjusting for potential confounders. Antibiotic exposure in categorical and continuous terms (spline) was investigated for pattern of risk, stratified by specific tumour location. Findings: 28,980 CRC cases and 137,077 controls were identified. Oral antibiotic use was associated with CRC risk, but effects differed by anatomic location. Antibiotic use was found to be associated with excess risk of colon cancer in a dose-dependent fashion (Ptrend 60 days (Adjusted Odds Ratio [AOR], 0·85, 95% CI 0·79-0·93) as compared with no antibiotic exposure. Penicillins were associated with increased risk of colon cancer (AOR,1·09, [1·05-1·13]) whereas tetracyclines were associated with risk reduction for rectal cancer (AOR, 0·90, [0·84- 0·97]). Significant interactions were detected between antibiotic use and tumour location (colon vs rectum, Pinteraction ten years before diagnosis (AOR, 1·17, [1·06-1·31]). Interpretation: Oral antibiotic use is associated with an increased risk of colon cancer risk but a reduced risk for rectal cancer. This effect heterogeneity may suggest differences in gut microbiota and carcinogenesis mechanisms along the lower intestine tract. Funding Statement: This project was funded by Johns Hopkins Fisher Center Discovery Program and Bloomberg~Kimmel Institute for Cancer Immunotherapy. Declaration of Interests: All authors have no directly relevant conflicts of interest to disclose. DP reports grant and patent royalties through institution from Bristol Myers Squibb, grant from Compugen, stock from Trieza Therapeutics and Dracen Pharmaceuticals, and founder 22 equity from Potenza; being consultant for Aduro Biotech, Amgen, Astra Zeneca (Medimmune/Amplimmune), Bayer, DNAtrix, Dynavax Technologies Corporation, Ervaxx, FLX Bio, Rock Springs Capital, Janssen, Merck, Tizona, and ImmunomicTherapeutics; being scientific advisory board of Five Prime Therapeutics, Camden Nexus II, WindMil; being board of director for Dracen Pharmaceuticals outside the submitted work. SC reports being consultant for Novartis and Theravance outside the submitted work. CS reports grants from Bristol Myers Squibb for microbiome research outside the submitted work. All other authors have nothing to declare. Ethics Approval Statement: This study was approved by the Institutional Review Board of the Johns Hopkins University

Source to sink sandstone-mudstone proportion and facies distribution across a third-order clastic wedge, Cretaceous Western Interior Seaway

The Iles Clastic Wedge is a 500 m thick, 3 My duration, third-order sequence that built out eastward in the Cretaceous Western Interior Seaway. The wedge also contains high-frequency regressive-to-transgressive sequences that are irregularly stacked in a basinward-stepping pattern (lower limb) and in a landward-stepping pattern (upper limb). The entire wedge and the component cycles were analyzed in terms of vertically monitored sandstone-mudstone proportion, thickness, and facies distribution. The measured profiles through the Iles Clastic Wedge form a 300 km long, source-to-sink transect from southeast Rock Springs uplift, Wyoming to Kremmling, Colorado. The sandstone proportion in the entire wedge (and also in the basinward-stepping half of the wedge) attains a maximum in the proximal reaches (fluvial and tidal-fluvial/estuarine channels) of the study transect and decreases unsteadily toward the medial and distal zone. A slight secondary increase in sand proportion also appears irregularly in the medial shoreline zone. On the other hand, the sandstone proportion in the landward-stepping half of the wedge reaches a maximum in the medial (tidal-fluvial and estuarine channels and delta-front) to distal zone (basinal regressive delta) of the wedge and decreases slightly sourceward. Along individual fourth-order sequences, the sandstones and mudstones indicate a more nuanced partitioning, with three marked sandstone maxima (proximal, medial, and distal zones), separated by zones with abundant mudstone. These sandstone peaks are produced by the presence of fluvial and tidal-fluvial/estuarine channel sandstones in the most proximal zone, delta front/shoreface in the medial reaches, and basinal regressive delta front in the distal zone. The mudstone peaks represent the muddy, coal-bearing coastal plain and the prodelta area. This accentuated sandstone and mudstone partitioning at shorter time scales (few 100 Ky) becomes blurred at the longer time scale (3 My) because of the progressive basinward, then landward, offset of successive high-frequency sequences that form the larger clastic wedge.