Thesis (M.P.H.)--University of Michigan, 1944.

Thesis (M.P.H.)--University of Michigan, 1944.

Thesis (M.S.) -- Brigham Young University. / Bibliography: leaves 186-192.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 100-104). Also available on the World Wide Web.

xix, 189 p. : ill. (some col.), maps (some col.) / Caldera-forming eruptions are dramatic and destructive natural phenomena, causing severe and sustained consequences to society. This dissertation presents new geochemical and geochronologic data for caldera-forming tuffs and pre- and post-caldera rhyolites of the two youngest caldera complexes in the Snake River Plain (SRP) in the western USA: Heise (6.6-4.5 Ma) and Yellowstone (2.1-0.6 Ma). Caldera complex evolution at Heise and Yellowstone can be described by formation of 3-4 spatially overlapping "nested" calderas, successive collapse of intracaldera fill, and development of a large hydrothermal system. Comparison between Heise and Yellowstone reveals that late-stage rhyolite eruptions have drastic depletions in 18 O that require remelting of large volumes (1,000's of km 3 ) of hydrothermally altered rock. Archean xenoliths and Phanerozoic rocks of the crustal basement beneath the SRP province are not depleted in 18 O and therefore cannot be a source of these rhyolites. Isotopic mixing models indicate that early large-volume rhyolites are produced by melting and hybridization of the crust by mantle-derived basalt, and late-stage rhyolites tap hydrothermally altered portions of intracaldera rocks from previous eruptions. Caldera-forming eruptions at Heise culminated 4.45 Ma with eruption of the 1,800 km 3 Kilgore Tuff, the most voluminous 18 O-depleted rhyolite in the SRP and worldwide. O, Sr, and Nd isotope geochemistry, zircon ages, mineral and whole-rock geochemistry, and liquidus temperatures for Kilgore Tuff samples erupted >100 km apart are similar and/or overlapping within error, indicating derivation from a remarkably homogeneous low-δ 18 O magma reservoir (δ 18 O=3.4[per thousand]). Caldera-wide batch assembly and homogenization of variably 18 O-depleted melt pockets with diverse zircon populations can explain the Kilgore Tuff's genesis. Central Plateau Member (CPM) rhyolites at Yellowstone have the same timing (∼2 million years after the initiation of volcanism), magnitude of δ 18 O depletion (∼3[per thousand] depleted relative to normal rhyolites), and cumulative eruptive volume (∼4,000-4,500 km 3 ) as the Kilgore Tuff of the Heise volcanic field. Isotopic, age, and geochemical data for CPM rhyolites show that they become progressively more homogeneous and evolved from 260 ka to 75 ka. Whereas the Kilgore Tuff erupted climactically as an explosive caldera-forming tuff, CPM rhyolite eruptions record sequential, predominantly effusive, "snapshots" of magma assembly, homogenization, and differentiation. This dissertation includes co-authored materials both previously published and submitted for publication. / Committee in charge: Ilya Bindeman, Chairperson; Gregory Retallack, Member; Mark Reed, Member; W. Andrew Marcus, Outside Member

The Kinnikinic Formation of central Idaho is a sedimentary unit consisting principally of orthoquartzite. From its maximum measured thickness of 2285 feet in the central Lemhi Range near Gilmore, Idaho, it thins westward to 376 feet at the type section and southward to 326 feet near Arco, Idaho. Northeast of the Lemhi Range it occurs only as erosional remnants, due to pre-Devonian erosion. Both the lower and upper contacts of the Kinnikinic Formation are disconformable. The Kinnikinic Formation is light colored, predominately fine to medium grained, thin to medium bedded, and largely cemented by silica overgrowths. Some metamorphic recrystallization has occurred locally. Although parallel laminae and structureless beds predominate within primarily parallel bedding, omikron-type (underwater dune) cross-laminae are locally abundant. The sediments are moderately sorted to well sorted and both positively and negatively skewed. Cumulative-frequency probability curves illustrate traction, "saltation," and "suspension" populations; some thin sections indicate two "saltation" populations. An open-marine, shallow-shelfal environment influenced by high-energy (tidal?) currents is postulated for deposition of the Kinnikinic Formation on the basis of the lithlogic uniformity, lateral extent, sedimentary structure, trace fossils, and paleogeographic setting. The Swan Peak Formation of southeastern Idaho and north-central Utah is divisible into a lower member of dark gray shale and quartz silitite, a middle member of brown orthoquartzite and light-colored shale, and an upper member of white orthoquartzite. Correlation of the white, fine- to medium-grained quartzite in the Raft River Range with the Ordovician Eureka Quartzite, considered probable by Compton (1972), is here accepted. The relatively thin nature of the Eureka Quartzite in this area reflects lesser sedimentation rates relative to areas farther south and/ or post-depositional erosion. The Dayley Creek Quartzite of Armstrong (1968) in the Albion Range is complexly faulted; as mapped, all or most of it probably is not correlative with the Kinnikinic Formation. Quartzites in the lower thrust plate of the Phi Kappa Formation in central Idaho are not environmental equivalents of the Kinnikinic Formation to the east, even though they apparently are approximately time equivalent (Churkin, 1963a, pp. 1612-1615). Middle Ordovician, shallow-shelfal orthoquartzit.es (Kinnikinic Formation, upper member of the Swan Peak Formation, Eureka Quartzite, and Mount Wilson Quartzite of southern Canada) are considered to be one originally continuous genetic unit, based on age determinations of overlying and underlying units, disconformable lower and upper contacts, close physical resemblances, and the high probability they were principally derived from the same source area, possibly Cambrian sandstones in the Peace River-Athabasca Arch area of northern Alberta, Canada. The shelfal environment of the Middle Ordovician Cordilleran miogeosyncline can be divided into at least five major, distinctly separated, basins of deposition: (1) Alberta-British Columbia Basin; (2) Central Idaho Basin; (3} Southeastern Idaho Basin (herein proposed); (4) Northeastern Nevada Basin; and (5) Ibex Basin. Anomalously high percentages of undulatory quartz grains in Middle Ordovician orthoquartzites of the Cordilleran miogeosynclinal shelf are highly suggestive of straining in situ and are probably related to post-depositional conditions ranging from purely tectonic to intricate combinations of tectonic and nontectonic events.

The purpose of this study was twofold: to determine the attitudes of students toward different parts and methods of grading in LDS Seminary, and to determine if significant differences exist in attitudes of students toward their class and teacher when using different methods of grading including a suggested method.The study reported the areas most preferred by students about grading and the areas least preferred. It reported the evaluation of the suggested method of grading including those areas of most value to the students and those of least value.The suggested method of grading helped to raise the subjects' grades by getting them to do more work better but when analyzed statistically there seemed to be no significant difference in the students' attitudes. The suggested method did prove to be satisfactory and was rated highly by the students. It featured an improved grade score, multiple listing of grades on the report card, and communication of the approximate grade thoughout the term.Related literature revealed that grades and methods were variable, unreliable, and inconsistent. It was concluded that other factors were more important than grading methods to alter attitudes of students.

An analysis of the relative abundance of the prevalent species in 25 major plant communities of the Wasatch Mountains demonstrates that variation in species diversity is significantly correlated with many floral characteristics. Wind pollinated flowers decrease in abundance while animal pollinated flowers increase along the diversity gradient. Both relationships are highly significant statistically. Color diversity and species diversity are significantly and positively correlated in open communities but are not correlated in forest communities. The percent sum frequency of yellow and pink-magenta flowers decreased with increasing species diversity while blue and whitish flowers increased. Also, zygomorphic flowers and flowers in which access to the nectar supply is restricted by morphological barriers are positively correlated with species diversity. It is shown that wind pollinated flowers and entomophilous open flowers are significantly more abundant than animal pollinated flowers whose nectaries are morphologically restricted, Theoretical explanations are offered for these relationships.

xviii, 326 p. : ill. (some col.), maps. A print copy of this title is available through the UO Libraries under the call number: KNIGHT GN799 .F6 H46 2002 / Archaeological evidence indicates that cold storage of bison meat was consistently practiced on the eastern Snake River Plain over the last 8000 years. Recent excavations in three cold lava tube caves have revealed a distinctive artifact assemblage of elk antler tines, broken handstones, and bison bone in association with frozen sagebrush features. Similar evidence has also been discovered in four other caves within the region. A patch choice model was utilized in this study to address how the long-term practice of caching bison meat in cold caves may have functioned in prehistoric subsistence patterns. Because the net return rate for bison was critical to the model, the hunting success of fur trappers occupying the eastern Snake River Plain during the early 1800s, as recorded in their daily journals, was examined and quantified. According to the model, the productivity of cold storage caves must be evaluated against the productivity of other patches on the eastern Snake River Plain, such as ephemeral ponds and linear river corridors from season to season and year to year. The model suggests that residential bases occurred only within river resource patches while ephemeral ponds and ice caves would contain sites indicative of seasonal base camps. The predictions of the model were tested against documented archaeological data from the Snake River Plain through the examination of Geographic Information Systems data provided by the Idaho Bureau of Land Management. The results of this analysis indicate that seasonal base camps are directly associated with both ephemeral and perennial water sources, providing strong support for the model's predictions. Likewise, the temporal distribution of sites within the study area indicates that climate change over the last 8000 years was not dramatic enough to alter long-term subsistence practices in the region. The long-term use of multiple resource patches across the region also confirms that, although the high return rates for bison made them very desirable prey, the over-all diet breadth for the eastern Snake River Plain was broad and included a variety of large and small game and plant foods. Bison and cold storage caves were a single component in a highly mobile seasonal round that persisted for some 8000 years, down to the time of written history in the 19th Century. / Committee in charge: Dr. C. Melvin Aikens, Chair; Dr. Lawrence Sugiyama ; Dr. Jon Erlandson ; Dr. Dennis Jenkins ; Dr. Cathy Whitlock ;

Master of Arts / Department of Geography / Lisa M. Harrington / Hayscapes, or haying landscapes, are distinctive cultural landscapes that evolve through time as a result of technological changes in response to economic realities. Since settlement began in the western United States, hay-making has gone through a number of mechanical revolutions that have given rise to an assortment of different methods employed in the process of gathering and storing hay. For this research, the changes in haying technology and resulting cultural landscapes are divided into four eras based on the haying methods of the time in western Montana and eastern Idaho. Common haying technology used in the study area at one time or another includes rudimentary devices, hay derricks, Beaverslides, overshots, swinging arm stackers, small, rectangular balers, tractors with front loader extensions, loaf stackers, round balers, large, rectangular balers, and forage harvesters (choppers). Farmers and ranchers create different hayscapes based on the technology used. There are different reasons for using different haying technologies, such as the type and size of agricultural operation, economics, and personal preference. Landscapes are documents, and by “reading” the haying landscape, we are able to acknowledge the story of the transition of life and ways of the past to present-day living of the people. Insights are discovered regarding past and present technologies and aspects of their social and economic systems. This study examines the different past and present haying landscapes of western Montana and eastern Idaho to better understand reasons and ways in which human activities have imprinted the landscape and given rise to distinct, and aesthetically pleasing, patterns on the earth’s surface.