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A survey of the vertebrate animals of Mount Jefferson, Oregon /Voth, Elver. January 1963 (has links)
Thesis (M.A.)--Oregon State University, 1963. / Typescript. Mounted photographs. Includes bibliographical references (leaves 169-174). Also available on the World Wide Web.
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A new model for the formation of Crater Lake Caldera, Oregon /Lidstrom, John Walter. January 1972 (has links)
Thesis (Ph. D.)--Oregon State University, 1972. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
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Magma chamber processes over the past 475,000 years at Mount Hood, Oregon : insights from crystal zoning and crystal size distribution studies /Darr, Cristina M. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 91-96). Also available on the World Wide Web.
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A model for the origin of calc-alkaline andesites at Crater Lake, OregonPinta, James, January 1981 (has links)
Thesis (Ph. D.)--Pennsylvania State University. / Includes bibliographical references (p. 118-124).
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Mount Mazama and Crater Lake : a study of the botanical and human responses to a geologic event /Green, Robyn A. January 1900 (has links)
Thesis (M.A.I.S.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references (leaves 115-124). Also available online.
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Physical characteristics of proximal Cleetwood airfall deposits, Crater Lake, OR : the transition from explosive to effusive eruption /Bourgeois, Renée Lise. January 1998 (has links)
Thesis (M.S.)--University of Oregon, 1998. / Typescript. Includes vita and abstract. CD-ROM contains SEM backscatter electron images for appendix B. Includes bibliographical references (leaves 183-186). Also available via the Internet.
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The effects of the Mazama tephra-falls : a geoarchaeological approachMatz, Stephan E. 28 May 1987 (has links)
About 7,000 years ago two major tephra-falls blanketed the
Pacific Northwest in volcanic ash. These two tephra-falls, identified
as the Llao and climatic tephra-falls, were a part of the eruptive
events that led up to the collapse of Mount Mazama to form Crater Lake
in the southern Oregon Cascades.
The tephra-falls occurred about 200
years apart at around 7,000 years B.P. and 6,800 years B.P. for the
Llao and climatic eruptions respectively.
The effects of the tephra-falls on the flora, fauna, and people of the period have been
characterized by different researchers as ranging from minimal to
catastrophic.
In an attempt to better understand the affects of these two
events on the flora, fauna, and people, a model is presented to help
organize the various lines of research into a coherent whole and to
suggest profitable areas of research which have not yet been completed.
The model is based on ecological and anthropological theory with a
strong reliance on analogy with modern ecosystems and volcanic hazards
research.
The model makes use of the ecosystem concept as the framework
for the interaction of the abiotic, or nonliving habitat, with the
biotic, or living system. The biotic organisms are adapted to the
characteristics of the abiotic habitat and in many respects the
composition, frequencies, and distributions of biotic organisms are
determined by their tolorance levels to these characteristics. Tephra-falls act as environmental disturbances which change the abiotic
habitat of the ecosystem. Therefore, any changes caused by such
a disturbance in the abiotic characteristics that are not optimal or
are outside of the tolorance limits of the biotic (flora and fauna)
components should cause changes in the composition, distribution, and
frequency of organisms within the ecosystem. The changes brought
about by the tephra-falls may be described by successional and
evolutionary processes through analysis of pollen and faunal remains,
population demography as described by mortality profiles, and research
into the reaction of specific flora and fauna within adaptational
types to the properties of tephra-falls and the tephra as a soil
body.
The state factors used to describe the abiotic component of the
ecosystem are: time, distribution, material properties, climate, and
geomorphology. The state factor of time involves the determination
of the occurrence in time of the event(s), the duration of the event(s),
the season of occurrence of the event(s), and the residence time of
tephra in the ecosystem. This state factor is used to define the
specific point in time and duration of the effects of the tephra-fall(s) for individual ecosystems. The state factor of distribution
describes the aerial extent and thickness of the air-fall deposits.
This state factor determines the extent of the initial disturbance.
The state factor of climate describes the specific components of
rainfall, wind, and temperature which control ecosystem composition
and development, and the changes to the climate which may have occurred
due to volcanic aerosols associated with the eruption. The state
factor of geomorphology describes the location of tephra and nontephra
bodies across the landscape and through time as the tephra is reworked
by wind, water, and gravity from the initial air-fall positions. The
determination of the long term distribution of the tephra is important
in determining post-event influences on ecosystems as described by
the material properties of the tephra.
It is argued that most people were not greatly harmed by the
Mazama tephra-fall events themselves, but instead may have been
greatly affected by a loss of food resources during and after the
events. Changes in food resource availability and exploitation
locations due to the tephra-falls may have resulted in changes in
both settlement and subsistence activities. Changes in settlement and
subsistence activities may be seen in a corresponding change in
differential frequencies of functional tool types across space and
time. The kind and amount of expected changes in settlement and
subsistence systems are linked to distance from the source of the
tephra, the stability and compostion of pre-disturbance ecosystems,
the types and intensity of resource exploitation, and the amount of
variability in subsistence and settlement traits which were available
to the sociocultural system. / Graduation date: 1988
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Controls on eruption style and magma compositions at Mount Hood, OregonKoleszar, Alison M. 21 July 2011 (has links)
This study is an effort to characterize the magma sources, plumbing system, and eruptive behavior of Mount Hood, a low-explosivity recharge-dominated volcano in the Oregon Cascades. The three manuscripts in this dissertation make use of melt inclusion data, phenocryst compositions, and whole rock petrology and geochemistry to build a schematic model of plumbing, mixing, and eruption at Mount Hood.
Volatile contents in melt inclusions were measured by Fourier Transform Infrared Spectroscopy (FTIR) and Secondary Ion Mass Spectometry (SIMS). These measurements indicate that the pre-eruptive volatile contents at Mount Hood are comparable to concentrations in more explosive volcanoes, and do not sufficiently explain the low explosivity of Mount Hood. Measured H₂O contents were also used to test the validity of multiple different hygrometers.
Various geothermobarometers were applied to the melt inclusions and phenocrysts from Mount Hood, and demonstrate that pre-eruptive temperatures increase
by 100-150 ̊C immediately after mafic recharge, which occurs days to weeks prior to eruption and is accompanied by a 5-10 fold decrease in magma viscosity. Numerical simulations of magma ascent indicate that magma fragmentation is significantly delayed with this magnitude of pre-eruptive heating, which reduces the likelihood of explosive eruption.
Analyses of amphibole demonstrate two markedly different populations, which correspond to different magma compositions, temperatures, and pressures. Pressure and temperature calculations were compared to other geothermobarometers to crosscheck the validity of these results and generally agreed well.
Trace element concentrations in lavas, enclaves, and inclusions from Mount Hood confirm previous models for simple binary mixing at Mount Hood. A linear regression technique for extrapolating the major element contents of the mixing endmembers works acceptably well to characterize the trace element budgets of these endmembers.
Additionally, we observe that the "recharge filter" that is responsible for the compositionally monotonous lavas at Mount Hood is also the likely cause of long-term low explosivity, and is indicative of a two-part magma plumbing system that may be a general model for a number of other recharge-dominated arc volcanoes. The results presented in this dissertation, in concert with previous results by other authors, converge on a generally consistent model for the production, hybridization, and eruption of intermediate lavas at Mount Hood and elsewhere. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from Sept. 16, 2011 - March 16, 2012
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Multicomponent chemical equilibrium modeling of the fluids and U-TH geochrnology of authigenic mineralization in geothermal systems /Hull, Carter Dean. January 1990 (has links)
Thesis (Ph. D.)--University of Oregon, 1990. / Typescript (photocopy). Presented to the Department of Geological Sciences and the Graduate School of the University of Oregon in partial fulfillment of the requirements for the degree of Doctor of Philosophy. Includes bibliographical references (leaves 157-164).
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Ambivalent Landscapes: An Historical Geography of Recreation and Tourism on Mount Hood, OregonMitchell, Ryan Franklin 01 June 2005 (has links)
Mount Hood is an Oregon icon. The mountain has as long and rich a history of recreation and tourism as almost any other place in the American West. But contemporary landscapes on Mount Hood reveal a recreation and tourism industry that has struggled to assert itself, and a distinct geographic divide is evident in the manner in which tourism has been developed. Why? In this study I chronicle the historical geography of recreation and tourism on Mount Hood. I examine the evolution of its character and pattern, and the ways in which various communities have used it to invest meaning in the places they call home. Despite the efforts of early boosters, Mount Hood has never been home to an elite destination resort like Aspen, Sun Valley, or Vail. Instead, modest recreation developed alongside timber and agriculture, and today the area is primarily a regional attraction. Unlike destinations with national and international clienteles that play a significant role in shaping lives and landscapes, local and regional interests are the primary drivers of recreation and tourism on Mount Hood. Communities on the mountain have incorporated the industry into their lives and landscapes to varying degrees. Mount Hood is also inextricably tied to Portland, and as an integral part of the city's history and identity, reflects its residents' tastes, values, and priorities. This combination of local and metropolitan interests has left an imprint on Mount Hood that reflects tensions and contradictions that define Oregon in the early twenty-first century: past vs. future, old vs. new economies, urban vs. rural inclinations, progress vs. status quo, and upscale vs. modest tastes. Spatially, temporally, and psychologically, Mount Hood straddles the divide between two visions: a service-based economy in the Willamette Valley, heavily dependent on technology, and a traditional, resource-based economy in much of the rest of the state.
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