Global ETD Search

131	Fluvial Architecture and Reservoir Modeling Along the Strike Direction of the Trail Member of the Ericson Sandstone, Mesaverde Group in Southwest Wyoming Trevino, April Anahi 01 July 2019 (has links) The Trail Member of the upper Cretaceous Ericson Sandstone, part of the Mesaverde Group, is exposed along hundreds of square kilometers through Wyoming along the flanks of several Laramide structural uplifts. This presents a unique opportunity to study the detailed architecture based on bed-scale heterogeneity and better assess the reservoir potential of these strata in outcrop exposure on a regional-scale, and to then relate these observations to producing fields nearby. The fluvial-dominated Trail Member formed as sediments traveled from the active Sevier thrust belt to the Cretaceous Interior Seaway, forming a basinward progradational clastic wedge along a relatively high gradient. The high energy, tectonically active setting led to preservation of sand-rich, often compositionally immature fluvial strata. Though there is an abundance of sand-rich strata in the Trail Member, production from this interval has been unpredictable in current and past fields such as the Trail Unit of southwestern Wyoming.Twelve detailed stratigraphic columns were described at three sites along the eastern flank of the Rock Springs Uplift to show facies heterogeneity beyond what is often available through wells, 69 hand samples were collected for determination of porosity and permeability, and photogrammetric characterization was performed at the three sites. Average porosity decreases along strike from north to south along with net-to-gross. The vertical changes in fluvial architecture within the Trail Member reflect changes in available accommodation. While thickness of the Trail Member is highly variable, ranging between 79 to 108 meters across the study area, there is an overall trend of thickening to the south. Although the character of the Trail strata changes appreciably along strike direction, this interval is consistently rich in sand, and grain size does not change drastically along the length of observed outcrops. This study demonstrated that spatial variability in the thickness, local accommodation, porosity, and net-to-gross of the Trail Member, as well as temporal variability in the amount and character of reservoir sands and channel stacking patterns play an important role in the unpredictability of this reservoir. This study will enable reservoir modeling and aid in future exploration projects within the Trail Member and other comparable systems with similar fluvial architecture and internal heterogeneity. Trail Member Ericson Sandstone Mesaverde Group Wyoming Laramide structural uplifts Cretaceous Interior Seaway Rock Springs Uplift net-to-gross temporal variability reservoir modeling fluvial architecture Geology Physical Sciences and Mathematics
132	Mountains as crossroads : temporal and spatial patterns of high elevation activity in the Greater Yellowstone ecosystem, USA Reckin, Rachel Jean January 2018 (has links) In the archaeological literature, mountains are often portrayed as the boundaries between inhabited spaces. Yet occupying high elevations may have been an adaptive choice for ancient peoples, as rapidly changing elevations also offer variation in climate and resources over a relatively small area. So what happens, instead, if we put mountain landscapes at the center of our analyses of prehistoric seasonal rounds and ecological adaptation? This Ph.D. argues that, in order to understand any landscape that includes mountains, from the Alps to the Andes, one must include the ecology and archaeology of the highest elevations. Specifically, I base my findings on new fieldwork and lithic collections from the Absaroka and Beartooth Mountains in the Greater Yellowstone Ecosystem (GYE) of the Rocky Mountains, which was a vital crossroads of prehistoric cultures for more than 11,000 years. I include five interlocking analyses. First, I consider the impacts of anthropogenic climate change on high elevation cultural resources, focusing on the diminishing resiliency of ancient high elevation ice patches and the loss of the organic artifacts and paleobiological materials they contain. Second, I create a dichotomous key for chronologically typing projectile points, suggesting a methodological improvement for typological dating in the GYE and for surface archaeology more broadly. Third, I use obsidian source data to consider whether mountain people were a single, unified group or were represented by a variety of peoples with different zones of land tenure. Fourth, I consider high elevation occupation in both mountain ranges as part of the seasonal round, using indices of diversity in tool types and raw material to study how the duration of those occupations changed through time. And, finally, I test the common contention that ancient people primarily used mountains as refugia from extreme climatic pressure at lower elevations. Ultimately, I find that, in both mountain ranges, increased high elevation activity is most highly correlated with increased population, not with hot, dry climatic conditions. In other words, the mountains were more than simply refugia for plains or basin people to occupy when pressured by climatic hardship. In addition, between the Absarokas and the Beartooths the evidence suggests two different patterns of occupation, not a monolithic pan-mountain adaptation. These results demonstrate the potential contributions of surface archaeology to our understanding of prehistory, and have important implications for the way we think about mountain landscapes as peopled spaces in relation to adjacent lower-elevation areas.
133	Politics and the Colorado River Steiner, Wesley E. 23 April 1971 (has links) From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / The Colorado River is the only major stream in the U.S. whose water supply is fully utilized. This distinction has brought the Colorado more than its share of controversy, within states, between states and between nations. The Colorado River compact, whose purpose was to equitably apportion the waters between the upper and lower basins and to provide protection for the upper basin through water reservation, was ratified by all states except Arizona, in 1923. Arizona finally ratified it in 1944. The history of controversies and negotiation concerning the compact are outlined through the supreme court decision on march 9, 1964, which entitled California to 4.4 maf, Nevada to 0.3 maf and Arizona to 2.8 maf, of the first 7.5 maf available in the lower Colorado. Unfortunately, the court did not attempt to establish priorities in the event of shortage. The problem is complicated by an international treaty of 1944, guaranteeing Mexico 1.5 maf annually, except in years of unusual circumstances. Because Senator Connally of Texas was then chairman of the senate foreign relations committee and because the treaty allocated twice as much Colorado River water to Mexico as it was then using, it was argued that this treaty represented a tradeoff to Mexico, giving it less water from the Rio Grande in exchange for more water from the overburdened Colorado. Problems of inter-basin water transfer studies, uniform Colorado basin water quality standards and central Arizona project planning are discussed. Water resources development -- Arizona. Hydrology -- Arizona. Hydrology -- Southwestern states. Colorado River compact Colorado River basin Political aspects International waters Arid lands Arizona California Wyoming New Mexico Colorado Utah Nevada Inter-basin transfers Water law Pacific Northwest U. S. Mexico Water allocation (policy) Legal aspects Central Arizona project
134	A Water Supply Data Base Nunamaker, J. F., Pingry, David E., Riley, Rex 16 April 1977 (has links) From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / This paper describes a water supply data base being developed for the Colorado River Basin States by the University of Arizona under contract with the Electric Power Research Institute, Inc. This data base is a guide to existing natural, technical, economic, and legal water data and water data agencies in the states of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. Hydrology -- Arizona. Water resources development -- Arizona. Hydrology -- Southwestern states. Networks Design System analysis Colorado River Basin Water supply Basic data collections Information exchange Data collections Operations research Water data Model studies Regional analysis Arizona Colorado Utah New Mexico Nevada Wyoming Southwest US
135	The Provenance of Eocene Tuff Beds in the Fossil Butte Member of the Green River Formation of Wyoming: Relation to the Absaroka and Challis Volcanic Fields Chandler, Matthew R. 25 July 2006 (has links) (PDF) The Green River Formation was deposited between 53.5 and 48.5 Ma. The Angelo, Fossil Butte, and Lower members of the Green River Formation at Fossil Basin, preserve ash fall tuffs deposited in ancient Fossil Lake. 40Ar/39Ar dating of sanidine yielded eruptive ages of 51.29 ± 1.29 Ma and 52.20 ± 3.08 Ma for two of the tuff beds within Fossil Basin. Immobile element and mineral compositions of Fossil Basin tuffs indicate that most tuffs erupted from a subduction zone originally as rhyolites and dacites. X-ray diffraction analyses reveal that the tuffs' glassy matrices have been altered to illite, calcite, clinoptilolite, analcime, albite, and K-feldspar. The variable alteration of the tuff beds confirms previous studies of Fossil Lake's salinity fluctuation through time. One outcrop (FB-10), which was previously interpreted to represent the K-spar tuff, has biotite of different compositions from that in known K-spar tuff samples (FB-09 and FB-11). Tuff horizons from the Greater Green River Basin have feldspar and biotite compositions similar to those from tuffs in Fossil Basin and are interpreted to have the same eruptive sources. Based on age and proximity, the Absaroka and Challis volcanic fields are the likely sources of tephra deposits in Fossil Basin and the Greater Green River Basin. Calc-alkaline tephras in these lacustrine basins have similar magmatic characteristics to the tuff of Ellis Creek (48.4 ± 1.6 Ma) from the Challis volcanic field. However, major and trace element, and mineral compositions of Absaroka and Challis volcanic rocks are not distinctive enough to definitively determine the source of most Fossil Basin and Greater Green River Basin tephras. Two samples, FB-10 from Fossil Basin and WN-79.15 from the Greater Green River Basin, have compositions similar to calc-alkaline magmas, but have some mineral compositions with A-type chemical affinities; consequently we conclude that they were erupted from volcanoes within the Challis volcanic field. Compositions of Challis volcanic rocks may have important implications for the development of a slab window in western North America during the Eocene. Compositional variation of Challis volcanic rocks through time indicates that calc-alkaline rocks with a slight A-type component erupted early in its history, and as the slab window matured the Challis volcanic field dominantly erupted rocks with a more A-type chemical affinity. A slab window may have developed due to the Farallon slab subducting at a shallow angle beneath the North American plate, and gravity may have caused it to break to the north. Through time the slab could have torn to the south and by 50 Ma the slab window would have been opening beneath the Challis volcanic field. This would have erupted calc-alkaline magmas, but upwelling of the asthenosphere into the mantle wedge (beneath the North American plate) would have introduced A-type magmatism into the magmatic system. By 45 Ma, the slab would have matured and opened sufficiently beneath the Challis volcanic field to replace calc-alkaline magmatism with, first "transitional" magmatism, and then A-type magmatism as evident in the youngest Challis tuffs. Fossil Butte National Monument Fossil Basin Green River Formation Fossil Butte Member Absaroka volcanic field Challis volcanic field Absaroka Challis Eocene volcanic rocks slab window Greater Green River Basin Wyoming Lake Gosiute Fossil Lake altered tuff beds alteration in volcanic rocks Geology
136	Geology of the Phil Pico Mountain Quadrangle, Daggett County, Utah, and Sweetwater County, Wyoming Anderson, Alvin D. 25 April 2008 (has links) (PDF) Geologic mapping in the Phil Pico Mountain quadrangle and analysis of the Carter Oil Company Carson Peak Unit 1 well have provided additional constraints on the erosional and uplift history of this section of the north flank of the Uinta Mountains. Phil Pico Mountain is largely composed of the conglomeratic facies of the early Eocene Wasatch and middle to late Eocene Bridger Formations. These formations are separated by the Henrys Fork fault which has thrust Wasatch Formation next to Bridger Formation. The Wasatch Formation is clearly synorogenic and contains an unroofing succession from the adjacent Uinta Mountains. On Phil Pico Mountain, the Wasatch Formation contains clasts eroded sequentially from the Permian Park City Formation, Permian Pennsylvanian Weber Sandstone, Pennsylvanian Morgan Formation, and the Pennsylvanian Round Valley and Mississippian Madison Limestones. Renewed uplift in the middle and late Eocene led to the erosion of Wasatch Formation and its redeposition as Bridger Formation on the down-thrown footwall of the Henrys Fork fault. Field observations and analysis of the cuttings and lithology log from Carson Peak Unit 1 well suggest that initial uplift along the Henrys Fork Fault occurred in the late early or early middle Eocene with the most active periods of uplift in the middle and late Eocene (Figure 8, Figure 24, Appendix 1). The approximate post-Paleocene throw of the Henrys Fork fault at Phil Pico Mountain is 2070 m (6800 ft). The Carson Peak Unit 1 well also reveals that just north of the Henrys Fork fault at Phil Pico Mountain the Bridger Formation (middle to late Eocene) is 520 m (1710 ft) thick; an additional 460 m (1500 ft) of Bridger Formation lies above the well on Phil Pico Mountain. Beneath the Bridger Formation are 400 m (1180 ft) of Green River Formation (early to middle Eocene), 1520 m (5010 ft) of Wasatch Formation (early Eocene), and 850 m (2800 ft) of the Fort Union Formation (Paleocene). Stratigraphic data from three sections located east to west across the Phil Pico Mountain quadrangle show that the Protero-zoic Red Pine Shale has substantially more sandstone and less shale in the eastern section of the quadrangle. Field observations suggest that the Red Pine Shale undergoes a facies change across the quadrangle. However, due to the lack of continuous stratigraphic exposures, the cause of this change is not known. Eocene Red Pine Shale Uinta Mountains Bridger Formation Wasatch Formation Henrys Fork Fault Uplift uplift history anticline syncline Laramide Green River Formation Bishop Conglomerate inverted cobble stratigraphy unroofing unroofing sequence conglomerate Phil Pico Mountain Flaming Gorge Utah Wyoming Paleocene clast erosional history north flank facies change strike-slip fault Madison Limestone Weber Sandstone Vr VrTwo VrOne geologic mapping geology glacial deposits Smiths Fork Uinta thrust cuttings lithology log erosion Carson Peak well geologic map cross-section stratigaphy stratigraphic column unit descriptions tectonic history Tertiary depositional deposition Proterozoic Precambrian Geology

Page generated in 0.0425 seconds