scholarly journals The history of a portion of Yampa River, Colorado, and its possible bearing on that of Green River

10.3133/pp90k ◽  
1915 ◽  
pp. 183-189
Author(s):  
E.T. Hancock
Keyword(s):  
Green River ◽  
History Of ◽  
Yampa River

Paleontology and stratigraphy of Middle Eocene rock units in the southern Green River and Uinta Basins, Wyoming and Utah

2017 ◽  
Vol 4 ◽  
pp. 1-53 ◽  
Author(s):  
Paul Murphey ◽  
K.E. Townsend ◽  
Anthony Friscia ◽  
James Westgate ◽  
Emmett Evanoff ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Middle Eocene ◽  
Green River Basin ◽  
Green River ◽  
Scientific Exploration ◽  
History Of ◽  
Climatic History ◽  
Field Excursion ◽  
Land Mammal ◽  
Bridger Formation

The Bridger Formation is restricted to the Green River Basin in southwest Wyoming, and the Uinta and Duchesne River Formations are located in the Uinta Basin in Utah. These three rock units and their diverse fossil assemblages are of great scientific importance and historic interest to vertebrate paleontologists. Notably, they are also the stratotypes from oldest to youngest for the three middle Eocene North American Land Mammal Ages—the Bridgerian, Uintan, and Duchesnean. The fossils and sediments of these formations provide a critically important record of biotic, environmental, and climatic history spanning approximately 10 million years (49 to 39 Ma). This article provides a detailed field excursion through portions of the Green River and Uinta Basins that focuses on locations of geologic, paleontologic, and historical interest. In support of the field excursion, we also provide a review of current knowledge of these formations with emphasis on lithostratigraphy, biochronology, depositional, and paleoenvironmental history, and the history of scientific exploration.

Deviation Forces From the Wedge Penetration Failure of Anisotropic Rock

1973 ◽  
Vol 95 (4) ◽  
pp. 1093-1100 ◽  
Author(s):  
W. B. Bradley
Keyword(s):  
Time History ◽  
Theoretical Work ◽  
Drill String ◽  
Triaxial Tests ◽  
Maximum Deviation ◽  
Anisotropic Rock ◽  
Green River ◽  
Rock Interaction ◽  
Confining Pressures ◽  
History Of

Deviation of boreholes is caused by drill string flexibility and the interaction between the drill bit and the formation being drilled. While work has been devoted to the analysis of drill string mechanics, less work has been directed toward the understanding of bit rock interaction. This paper presents the results from some experimental work on the deviation forces and chip volumes generated by the wedge penetration of anisotropic rock. The single blow wedge penetration tests were conducted on blocks of Green River shale cut to simulate formation dip angles from 0 to 90 deg. During the tests, the time history of the force required to penetrate the rock, together with the deviation forces perpendicular and parallel to the strike of the formation were recorded. Tests were conducted using wedges with 30 and 60 deg included wedge angles at atmospheric and 10,000 psi confining pressures. In conjunction with these tests, triaxial tests were performed to determine the failure characteristics of this particular rock. Results from these tests showed that appreciable deviation forces were generated by the 30 and the 60 deg wedges at both confining pressures. Maximum deviation forces were generated in the 30 deg dip region and in the 60 deg dip region, with the deviation forces tending to zero at 0 deg, 90 deg, and in the region of 45 deg. The results are in general agreement with field observations. The volumes generated correlate with the measured forces as well as field experience. Predominant chip volumes were created on the updip side of the tooth at low dip angles and on the downdip side of the tooth at high dip angles for both tooth geometries. Published predictions on the advantages of 60 deg teeth for deviation control were found to be in disagreement with experimental results. When combined with the measured rock failure properties, the theoretical work upon which the above predictions were based did predict deviation forces in qualitative agreement with the experimentally determined values.

scholarly journals Paleontology and stratigraphy of Middle Eocene rock units in the southern Green River and Uinta Basins, Wyoming and Utah

2017 ◽  
Vol 4 ◽  
pp. 1-53 ◽  
Author(s):  
Paul C. Murphey ◽  
K.E. Beth Townsend ◽  
Anthony R. Friscia ◽  
James Westgate ◽  
Emmett Evanoff ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Middle Eocene ◽  
Green River Basin ◽  
Green River ◽  
Scientific Exploration ◽  
History Of ◽  
Climatic History ◽  
Field Excursion ◽  
Land Mammal ◽  
Bridger Formation

The Bridger Formation is restricted to the Green River Basin in southwest Wyoming, and the Uinta and Duchesne River Formations are located in the Uinta Basin in Utah. These three rock units and their diverse fossil assemblages are of great scientific importance and historic interest to vertebrate paleontologists. Notably, they are also the stratotypes from oldest to youngest for the three middle Eocene North American Land Mammal Ages—the Bridgerian, Uintan, and Duchesnean. The fossils and sediments of these formations provide a critically important record of biotic, environmental, and climatic history spanning approximately 10 million years (49 to 39 Ma). This article provides a detailed field excursion through portions of the Green River and Uinta Basins that focuses on locations of geologic, paleontologic, and historical interest. In support of the field excursion, we also provide a review of current knowledge of these formations with emphasis on lithostratigraphy, biochronology, depositional, and paleoenvironmental history, and the history of scientific exploration.

scholarly journals Dam tailwaters compound the effects of reservoirs on the longitudinal transport of organic carbon in an arid river

2015 ◽  
Vol 12 (8) ◽  
pp. 6081-6114
Author(s):  
A. J. Ulseth ◽  
R. O. Hall Jr.
Keyword(s):  
Organic Carbon ◽  
Base Flow ◽  
Green River ◽  
Transport And Transformation ◽  
Stream Discharge ◽  
River Reservoir ◽  
Gorge Reservoir ◽  
Flaming Gorge ◽  
Early Snowmelt ◽  
Yampa River

Abstract. Reservoirs on rivers can disrupt organic carbon (OC) transport and transformation, but less is known how downstream river reaches directly below dams contribute to OC processing than reservoirs alone. We compared how reservoirs and their associated tailwaters affected OC quantity and quality by calculating particulate (P) OC and dissolved (D) OC fluxes, and measuring composition and bioavailability of DOC. We sampled the Yampa River near Maybell, Colorado, USA and the Green River above and below Fontenelle and Flaming Gorge reservoirs, and their respective tailwaters from early snowmelt to base flow hydrological conditions. In unregulated reaches (Yampa River, Green River above Fontenelle reservoir), DOC and POC concentrations increased with snowmelt discharge. POC and DOC concentrations also increased with stream discharge below Fontenelle reservoir, but there was no relationship between DOC and stream flow below Flaming Gorge reservoir. The annual load of POC was 3-fold lower below Fontenelle Reservoir and nearly 7-fold lower below Flaming Gorge reservoir, compared to their respective upstream sampling sites. DOC exported to downstream reaches from both reservoirs was less bioavailable, as measured with bioassays, than DOC upriver of the reservoirs. Lastly, tailwater reaches below the reservoirs generated OC, exporting 1.6–2.2 g C m−2 d−1 of OC to downstream ecosystems. Changes in total fluxes from upstream to downstream of reservoirs and their tailwaters do not represent the simultaneous transformation and production of OC, which may lead to the underestimation of the quantity of OC mineralized, transformed, or retained in coupled river-reservoir-tailwater ecosystems.

Sign in / Sign up

Export Citation Format

Share Document