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1. Cambrian trilobites and associated fossils from the Uinta Mountains of Utah (USA)

   https://doi.org/10.1017/jpa.2023.82  

   Foster, John R; Sundberg, Frederick A; Hagadorn, James W (January 2024, Journal of Paleontology)

   Abstract Fossils are rare in Cambrian strata of the Uinta Mountains of northeastern Utah, and are important because they can help integrate our understanding of laterally adjacent but discontiguous rock units, e. g., the Tintic Quartzite of Utah and the Lodore Formation of Utah-Colorado. New body fossils from strata previously mapped as Tintic or Cambrian Undifferentiated, but here interpreted as the Ophir Formation, include indeterminate hyoliths and hyolithids, brachiopods including a linguloid, and the trilobitesTrachycheilusResser, 1945 andElrathiellaPoulsen, 1927. The last two assign these strata to theEhmaniellaBiozone (uppermost Wuliuan Stage; Miaolingian Series) or traditional Laurentian middle Cambrian. These data, together with fossil occurrences elsewhere in Utah, require that the Tintic Quartzite was deposited prior to and/or during the early Wuliuan, and suggest that the unit could be correlative to much of the Lodore Formation of Utah and Colorado. 

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2. InSAR-based characterization of rock glacier movement in the Uinta Mountains, Utah, USA

   https://doi.org/10.5194/tc-15-4823-2021  

   Brencher, George; Handwerger, Alexander L.; Munroe, Jeffrey S. (January 2021, The Cryosphere)

   Abstract. Rock glaciers are a prominent component of many alpine landscapes andconstitute a significant water resource in some arid mountainenvironments. Here, we employ satellite-based interferometric syntheticaperture radar (InSAR) between 2016 and 2019 to identify and monitor activeand transitional rock glaciers in the Uinta Mountains (Utah, USA), an area of∼3000 km2. We used mean velocity maps to generate aninventory for the Uinta Mountains containing 205 active and transitional rockglaciers. These rock glaciers are 11.9 ha in area on average andlocated at a mean elevation of 3308 m, where mean annual airtemperature is −0.25 ∘C. The mean downslope velocity for theinventory is 1.94 cm yr−1, but individual rock glaciers have velocities ranging from0.35 to 6.04 cm yr−1. To search for relationships with climaticdrivers, we investigated the time-dependent motion of three rock glaciers. Wefound that rock glacier motion has a significant seasonal component, withrates that are more than 5 times faster during the late summer compared to therest of the year. Rock glacier velocities also appear to be correlated withthe snow water equivalent of the previous winter's snowpack. Our resultsdemonstrate the ability to use satellite InSAR to monitor rock glaciers overlarge areas and provide insight into the environmental factors that controltheir kinematics. 

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3. Contemporary movement of rock glaciers in the La Sal and Uinta Mountains, Utah, USA

   https://doi.org/10.1016/j.qsa.2024.100188  

   Munroe, Jeffrey S; Handwerger, Alexander L (June 2024, Quaternary Science Advances)

   Rock glaciers are common landforms in mountainous areas of the western US. The motion of active rock glaciers is a key indicator of ice content, offering connections to climate and hydrologic systems. Here, we quantified the movement of six rock glaciers in the La Sal and Uinta Mountains of Utah through repeat differential GPS surveying. Networks of 10–41 points on each rock glacier were surveyed in September 2021; July 2022; September 2022; and July 2023. We found that all features are moving with average annual rates of motion from 1.5 ± 0.8 to 18.5 ± 7.5 cm/yr. Rock glaciers move up to 3× faster in the summer than in the winter, and rates of motion were greater in 2023 after a winter with above-average snowfall, emphasizing the role of liquid water availability. Velocities of individual points in the winter of 2021–22 are positively correlated with velocities during the winter of 2022–23, suggesting that spatial variability of motion is not stochastic, but rather reflects internal properties of each rock glacier. Bottom temperature of snow measurements during winter, and the temperature of springs discharging water in summer, suggest that these rock glaciers contain modern permafrost. Radiocarbon data document advance of one rock glacier during the Little Ice Age. Our GPS dataset reveals complicated patterns of rock glacier movement, and the network of survey points we established will be a valuable baseline for detecting future cryosphere change in these mountains. 

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4. Multiproxy lacustrine records of post-glacial environmental change from the Uinta Mountains, Utah, USA

   https://doi.org/10.1130/B35056.1  

   Munroe, Jeffrey S.; Laabs, Benjamin J.C. (May 2019, GSA Bulletin)

   Abstract Twenty-one sediment cores were obtained from 20 lakes in the Uinta Mountains, Utah, USA. Depth-age models were developed using 14C dating, and sediments were analyzed for loss-on-ignition (LOI), carbon-nitrogen ratio (C:N), and grain size distribution. Although some of these cores have been considered individually in previous studies, here the entire set of cores is evaluated collectively to identify consistent patterns, commonalities, and trends in the post-glacial interval. All lakes accumulated substantially greater amounts of submicron-size clastic material before ca. 9.5 ka BP. This pattern is interpreted as a signal of prolonged landscape instability following deglaciation. Values of LOI and C:N exhibit a strong, positive correlation in nearly all lakes, indicating that organic matter accumulation is controlled by the influx of terrestrial material. In the six lakes exhibiting the strongest correlation, and featuring the most robust inflowing streams, median grain size and the abundance of sand increased between 10 and 6 ka BP, simultaneous with increases in LOI and C:N. This correspondence is interpreted as evidence for frequent high-intensity storms during the early Holocene, likely driven by enhanced monsoonal circulation. The early parts of five of the records contain a sharp increase in LOI. Lakes exhibiting this pattern are typically smaller and shallower, and are located in less rugged watersheds. Finally, all six cores from the western Uinta Mountains contain evidence for an environmental perturbation ca. 4.5 ka BP. Although the nature of this event is unclear, these lakes accumulated notably finer-grained sediment with less organic matter at this time. This analysis illuminates the post-glacial history of this strategically located mountain range, and underscores the value inherent in analyzing cores from multiple lakes when reconstructing paleoclimatic history. 

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5. The Last Pleistocene glaciation in the Uinta Mountains: updated chronology and connections to Lake Bonneville.

   Laabs, B.J.C. (January 2019, PROCEEDINGS VOLUME: 2018 LAKE BONNEVILLE GEOLOGIC CONFERENCE AND SHORT COURSE, October 3–6, 2018)