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Lake basin response to tectonic drainage diversion: Eocene Green River Formation, Wyoming A previously unidentified major sequence boundary within the Eocene Green River Formation separates fluctuating profundal facies of the Tipton Shale Member from evaporative facies of the Wilkins Peak Member. During deposition of the Tipton Shale Member, rivers entered the basin from the north, across the subdued Wind River Mountains, and deposited the southward prograding deltaic complex of the Farson Sandstone Member. Boulder-rich alluvial fan deposits overlie the Farson Sandstone adjacent to the Continental Fault, and correlate basinward to hypersaline lacustrine deposits of the Wilkins Peak Member. The alluvial fan deposits record a period of reverse motion on the Continental Fault and uplift of the southeastern... Categories: Publication; Types: Citation, Journal Citation; Tags: Evaporite, Journal of Paleolimnology, Lacustrine, Sequence boundary, Springer Netherlands, All tags... Tectonic control, Wilkins Peak, Fewer tags Complex caddisfly-dominated bioherms from the Eocene Green River Formation Complex, caddisfly-dominated (Insecta: Trichoptera) carbonate mounds up to 9 m tall and 40 m in diameter formed in the nearshore environment of Eocene Lake Gosiute. The mounds outcrop for 70 km in reef-like geometries along the northern margin of Lake Gosiute in Wyoming. The relationships among the caddisfly larvae, the benthic microbial mat and physicochemical nearshore processes of Eocene Lake Gosiute resulted in unique external and internal carbonate mound morphology. Externally, the large carbonate mounds are formed by the lateral and vertical coalescence of several layers of smaller columns. The smaller columns are generally 1?2 m tall and are 0.5?1 m in diameter. Each layer or generation of smaller columns... Categories: Publication; Types: Citation, Journal Citation; Tags: Green River Formation, Sedimentary Geology, Trichoptera, Tufa, Wyoming, All tags... bioherms, caddisfly, lacustrine, Fewer tags A multidisciplinary study of the Lower Cretaceous Cedar Mountain Formation, Mussentuchit Wash, Utah: a determination of the paleoenvironment and paleoecology of the Eolambia caroljonesa dinosaur quarry A quarry within the Cedar Mountain Formation in Mussentuchit Wash, Emery County, Utah, produced a fossil assemblage containing the remains of at least eight juvenile iguanodontid dinosaurs (Eolambia caroljonesa). The Cedar Mountain Formation lies stratigraphically between the Tithonian?Berriasian (Upper Jurassic) Brushy Basin Member of the Morrison Formation and the Cenomanian (Upper Cretaceous) Dakota Formation. Detailed stratigraphic, sedimentological, geochronological, palynological, and paleontological data have been collected along a measured section at the site of the Cifelli #2 Eolambia caroljonesa Quarry. These data provide a chronostratigraphic and a biostratigraphic framework for the Cedar Mountain Formation... Categories: Publication; Types: Citation, Journal Citation; Tags: 40Ar/39Ar, Albian, Angiospermae, Biostratinomy, Cedar Mountain Formation, All tags... Cenomanian, Cretaceous Research, Dakota Formation, Dinosaurs, Geochronology, Iguanodontid, Lacustrine, Mussentuchit Fauna, Mussentuchit Local Fauna, Paleoclimate, Paleoecology, Palynology, Yellow Cat Fauna, Fewer tags 40Ar/39Ar geochronology of the Eocene Green River Formation, Wyoming The deposits of Eocene Lake Gosiute that constitute the Green River Formation of Wyoming contain numerous tuff beds that represent isochronous, correlatable stratigraphic markers. Tuff beds selected for 40Ar/39Ar analysis occur within laminated mudstone, are matrix supported, and lack evidence of reworking. These tuffs contain 2%?15% euhedral phenocrysts of quartz, plagioclase, sanidine, biotite, and minor amphibole, pyroxene, and zircon, encased in a matrix of altered glassy ash. Air abrasion and handpicking under refractive- index oils were required to obtain clean, unaltered phenocrysts of sanidine. 40Ar/39Ar age determinations from single-crystal and <1 mg multigrain aliquots of sanidine and biotite allowed... Categories: Publication; Types: Citation, Journal Citation; Tags: 40Ar/39Ar, Early Eocene Climate Optimum, Geological Society of America Bulletin, Green River Formation, Wasatchian-Bridgerian, All tags... lacustrine, sedimentation rates, Fewer tags Eocene calibration of geomagnetic polarity time scale reevaluated: Evidence from the Green River Formation of Wyoming We reevaluate the Eocene geomagnetic polarity time scale on the basis of single-crystal 40Ar/39Ar ages for air-fall tuffs from the Wilkins Peak Member of the Green River Formation of Wyoming. Tuff 6 is dated as 49.1 � 0.2 Ma, and tuff 3 is dated as 50.4 � 0.3 Ma (maximum estimate). When combined with published magnetostratigraphic constraints, these age determinations suggest that the currently accepted age of chron C22r is 1.5?2.5 m.y. too old, which supports a significantly longer duration for the early Eocene, for the early Eocene climatic optimum, and the Wasatchian North American Land Mammal Age. Published in Geology, volume 32, issue 2, on pages 137 - 137, in 2004. Categories: Publication; Types: Citation, Journal Citation; Tags: Ar-Ar, Geology, Green River Formation, Wasatchian-Bridgerian, early eocene climate optimum, All tags... eocene, lacustrine, Fewer tags