It was the writer's purpose to determine the reason students discontinued seminary before obtaining a fourth-year certificate from the Burley L. D. S. Seminary between the years 1961-1965. In addition to this, means of helping to solve the problems of the students who discontinued seminary were sought. Questionnaires were sent to 92 students who had discontinued seminary; a questionnaire was also given to 61 students who were still in seminary. The results of these questionnaires were tabulated by the Brigham Young University Data Processing Service. Of the 92 students who discontinued seminary and received questionnaires, 66 (70 per cent) were returned.

Anhydrous ammonia (NH3) was tested as a potential replacement for residual, non specific toxicants as an effective control agent. It was postulated that NH3 would effectively control northern pocket gophers (Thomomys talpoides) and also act as a fertilizer for rangeland vegetation. Compound 1080 was selected as a standard for comparison of gopher control efficiency. Over 700 burrow systems were treated or monitored. Results showed compound 1080 to be 81 percent and NH3 45 percent efficient in controlling gophers. Although fertilizing effects of NH3 were positive, the low control efficiency and high application costs make NH3 an unlikely replacement for the now restricted residual toxicants.

The purpose of this study was to determine the ecological factors existing within the chaparral community. The present status of the vegetation in a one-acre exclosure was analyzed and recorded so that subsequent improvement or eterioration might be noted. A brief history of the area, the weather, and the geology are presented. Many other aspects of the problems enumerated in the introduction need to be studied. This study provides a foundation for a more detailed study of the vegetation which may be undertaken at a future date.

This vegetational analysis is concerned with changes which have cocurred since 1949 in a mountain brush community within an exclosure in the central Wasatch Mountains. The exclosure, established in 1949, is located in Pole Canyon on lower Provo Canyon. Two major studies have been conducted previously, but it has been nine years since the last intensive work was done. Several major changes occurring during the eighteen year period are evident and are described.

This is a comparative study of the vegetation and soils of an exclosure in the mountain brush vegetation of the Wasatch Mountains, Utah. The exclosure was fenced and initially analyzed during the summers of 1949-1950. The study area is located in Pole Canyon in the Uinta National Forest, a few miles northeast of Provo, Utah. The dominant woody species of the vegetation in the exclosure are big toothed maple (Acer grandidentatum) and Gambel oak (Quercus gambelii). After settlement of the area in and around Provo, Pole Canyon became overgrazed by livestock. Since 1949 the area has been protected from grazing. The purpose of this study was to analyze the vegetative and environmental relationships in the exclosure and to determine any changes occurring since the initial study by comparison with the results of the preliminary study.

Dense array seismic techniques can be applied to multiple types of seismic data to understand regional tectonic processes via analysis of crustal velocity structure, imaging reflection surfaces, and calculating high-resolution hypocenter locations. The two regions presented here include an intraplate seismogenic fault zone in Virginia and a steep cratonic margin in eastern Oregon and Idaho. The intraplate seismicity study in Virginia consisted of using 201 short-period vertical-component seismographs, which recorded events as low as magnitude -2 during a period of 12 days. Dense array analysis revealed almost no variation in the seismic velocity within the hypocentral zone, indicating that the aftershock zone is confined to a single crystalline-rock terrane. The 1-2 km wide cloud of hypocenters is characterized by a 29° strike and 53° dip consistent with the focal mechanism of the main shock. A 5° bend along strike and a shallower dip angle below 6 km points toward a more complex concave shaped fault zone. The seismic study in Idaho and Oregon was centered on the inversion of controlled-source wide-angle reflection and refraction seismic P- and S-wave traveltimes to determine a seismic velocity model of the crust beneath this part of the U.S. Cordillera. We imaged a narrow, steep velocity boundary within the crust that juxtaposes the Blue Mountains accreted terranes and the North American craton at the western Idaho shear zone. We found a 7 km offset in Moho depth, separating crust with different seismic velocities and Poisson's ratios. The crust beneath the Blue Mountains terranes is consistent with an intermediate lithology dominated by diorite. In the lower crust there is evidence of magmatic underplating which is consistent with the location of the feeder system of the Columbia River Basalts. The cratonic crust east of the WISZ is thicker and characterized by a felsic composition dominated by granite through most of the crust, with an intermediate composition layer in the lower crust. This sharp lithologic and rheologic boundary strongly influenced subsequent deformation and magmatic events in the region. / Ph. D. / Dense array seismic techniques involve using many instruments deployed closely together to record natural or man-made ground shaking. These techniques can be applied to different types of seismic data to understand the regional composition and behavior of the Earth’s crust, and identify locations where earthquakes have occurred. The two regions presented here include a zone in Virginia known to have small earthquakes and a location in eastern Oregon and Idaho where younger crust meets older crust across a very steep boundary. The seismicity study in Virginia consisted of using 201 instruments to record earthquake aftershocks with very small magnitudes during a period of 12 days. Dense array analysis techniques revealed almost no variation in the speed that seismic waves travel within the zone of aftershocks, indicating that the aftershocks are confined to a single crystalline-rock region. The 1-2 km wide zone of sub-surface aftershock locations is consistent with the rupture orientation of the main earthquake on 23 August 2011. The zone’s slightly concave shape indicates a complex region of rock movement. The seismic study in Idaho and Oregon was centered on analyzing seismic waves that are generated by explosions and travel through the crust, bending and reflecting when they pass through variations in the rock. We imaged a narrow, steep boundary that juxtaposes the younger Blue Mountains crust and the older North American craton at the western Idaho shear zone (WISZ). We found a sharp ~7 km step between the thicknesses of the two regions and different seismic velocities on either side of the boundary. The crust beneath the Blue Mountains terranes is consistent with an intermediate rock type dominated by diorite. In the lower crust there is evidence of a layer that is consistent with un-erupted material from the Columbia River Basalts. The continental crust east of the WISZ is thicker and dominated by granite through most of the crust, with an intermediate composition layer in the lower crust. This sharp boundary strongly influenced subsequent deformation and magmatic events in the region.

Veratrum californicum (common name: corn lily) is a wild plant species that grows in the Intermountain West, its range extending from British Columbia to Mexico. Corn lily is of interest because it has the potential to provide pharmaceutical precursors for use in the treatment of cancer. Pharmaceutical companies are currently running clinical trials of new drugs that use these precursors. As such, a sustainable supply of corn lily is needed if these drugs are ever to enter the market. Unfortunately, wild populations of corn lily will not be able to meet the market demand. Therefore, it is necessary that horticultural guidelines be established so that corn lily can be grown in an agricultural setting. Establishing irrigation criteria is one crucial component in this process, as corn lily grows in naturally wet areas and will most likely require supplemental irrigation in an agricultural setting. In order to determine the appropriate level of irrigation for corn lily, an appropriate range of irrigation levels to test in a field trial must be determined. Plant success as a function of irrigation level can then be measured. In order to determine what irrigation levels should be tested, the OSU Malheur Experiment Station monitored the natural environment of corn lily at a variety of locations over the course of four seasons. Results showed that for the majority of its growing season, corn lily occupies a narrow environmental niche where soil water tension ranges from 0 kPa to 30 kPa. With this information, irrigation levels ranging from 5 kPa to 30 kPa were chosen for irrigation trials. In 2009, corn lily plots were established at Ontario, Oregon and McCall, Idaho. Irrigation trials were run in 2010, 2011, and 2012 at Ontario and McCall. Plots were assigned to five irrigation treatments: 5 kPa (added halfway through the 2010 growing season), 10 kPa, 15 kPa, 20 kPa, and 30 kPa. Collectively, the data indicate that the 5 and 10 kPa treatments are most conducive to corn lily survival and growth. In addition, the observed data are consistent with the hypothesis that soil moisture levels in the first month of growth may be the most important determinant in plant growth and survival. / Graduation date: 2013

Rodent densities were estimated in the major vegetation types of the Snake River Birds of Prey Natural Area in 1975 and 1976 by a combination of live-trapping and kill-trapping. Only deer mice (Peromyscus maniculatus) were numerous enough to permit reliable density estimates. Relative densities of other rodent species were indicated by kill-trap capture rates. Densities of deer mice correlated well (r = 0.99) with kill-trap capture rates. The use of kill -trapping in place of live-trapping in 1976 permitted extensive sampling throughout the 1930 km2 study area. Differences were found among the major vegetation and land-use types in their ability to support the rodent species representing potential prey for feeding raptors.

The timing of motion on thrust faults in the Idaho-Wyoming-Utah (IWU) thrust belt comes from synorogenic sediments, apatite thermochronology and direct dating of fault rocks coupled with good geometrical constraints of the subsurface structure. The thermal history comes from the analyses of apatite thermochronology, thermal maturation of hydrocarbon source rocks and isotope analysis of fluid inclusions from syntectonic veins. New information from zircon fission track and zircon (U-Th)/He analysis provide constraints on the thermal evolution of the IWU thrust belt over geological time. These analyses demonstrate that the time-temperature pathway of the rocks sampled never reached the required conditions to reset the thermochronometers necessary to provide new timing constraints. Previous thermal constraints for maximum temperatures of IWU thrust belt rocks, place the lower limit at ~110°C and the upper limit at ~328°C. New zircon fission track results suggest an upper limit at ~180°C for million year time scales. ID-TIMS and LA-ICPMS of syntectonic calcite veins suggest that new techniques for dating times of active deformation are viable given that radiogenic isotope concentrations occur at sufficient levels within the vein material.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 280-298).