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Bathymetry and structure of San Clemente Island, California, and tectonic implications for the southern California continental borderlandRidlon, James Barr 24 November 1968 (has links)
Five lithologic units, ranging in age from Middle Miocene to Recent,
are defined on the basis of continuous seismic reflection profile records.
Two of the units are Miocene sedimentary and volcanic rocks that have been
truncated to form a major unconformity (post-orogenic surface) related to
the most recent major tectonism of the region. The remaining units are
post-orogenic unconsolidated sediments.
The fault pattern offshore is generally related to that exhibited on
the island. The pattern conforms to a wrench-fault system hypothesized
by Moody and Hill (1956) modified by a general north-south tensional fracturing.
The San Clemente Fault is assumed to be the primary wrench fault
of the system. Anomalies in the thicknesses and the structure of the
unconsolidated sediment and rock units tend to confirm the structural model.
A canyon (Eel Ridge Canyon) off the west side of San Clemente Island
appears to have been caused by pivotal faulting and erosion, and represents
a boundary between different structural trends north and south.
A prominent terrace around the island is postulated to have been
wave-cut during and since the Late Pleistocene. The island has been
tilted slightly to the west by Recent tectonism.
A steep magnetic gradient off the east side of the island is considered
the consequence of faulted volcanic flows comprising the island
itself and a deep basic rock mass responsible for a large positive magnetic
anomaly off the northwest side. Other magnetic anomalies reflect
major structural trends.
Earthquake epicenter data suggest a recent and possibly cyclical
occurrence of fault activity in the northern Continental Borderland
region and the study area. Fault offsets at the sea floor and earthquake
epicenters along the San Clemente fault zone imply recent adjustments
along the fault.
Wrench-fault movement resulting from a simple shear or shear couple
is considered to have caused the zone of brecciation along the San
Clemente Fault and produced the fault-trace curvature so evident in a
series of en echelon, northwest-striking major faults of the Borderland.
Tensile release during periods of wrench-fault development has been a
fundamental factor in the structural development of the Borderland
basins. The entire structure of the Continental Borderland is believed
to have developed by right-lateral movement along the series of wrench
faults. These faults are believed to have resulted from a translation
of force by sea-floor spreading originating on the East Pacific Rise in
the Gulf of California region. This force is considered to have moved
a northern Continental Borderland crustal plate westward by east to west
release along major wrench faults bordering the north and south ends of
this plate.
Sediments, transported along channels developed along faults in the
island block, were deposited in basins developed by faulting and folding
of the pre-orogenic rocks. Transportation appears to have been by means
of turbidity-current flows, sand flows, and slides. A maximum average
depositional rate of 35 to 47 centimeters per 1,000 years is estimated
for post-orogenic sediments.
The following findings are suggested for inclusion in the Neogene
history of the island: (1) the top 365 meters of Miocene andesitic lavas
were deposited above sea level and tend to become slightly more basic in
composition with depth; (2) subsidence of the island region and temporary
sea-level stand(s) occurred after the deposition of the volcanic rocks,
with possible periods of foundering to about the Late Pliocene; (3)
emergence, lengthy subaerial exposure, and a period of partial submergence
took place from about Late Pliocene through Early Pleistocene;
(4) a north-south compressive force developed or recurred across the
Borderland during Late Pliocene, developing the present northwest-southeast
and east-west wrench-fault systems that have been intermittently
active to the present time; (5) much of the present Borderland topography
formed during the Pleistocene to Recent. / Graduation date: 1969
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Evaluating space use and pesticide exposure risk for burrowing owls in an agricultural environmentGervais, Jennifer A. 22 April 2002 (has links)
Large burrowing owl (Aihene cunicularia) populations exist in areas of
intensive agriculture in California, and pesticide exposure has been identified as a
potential threat to population persistence. I evaluated breeding season use of
agricultural fields by adult male owls using radio telemetry, and examined egg
contaminant residues to estimate population-level effects on reproduction and
survival. Reproduction and survival were estimated annually, and an index of diet
was inferred from pellet samples. A total of 11 adult males in 1998 and 22 in 1999
were successfully radio-tracked. Mean fixed kernel home range sizes were 172 ha
(SE=68) in 1998 and 98 ha (SE=16) in 1999. Pellet analyses indicated a
substantial increase in the numbers of rodents consumed in 1999, associated with an
observed population explosion of California voles (Microtus calfornicus). Distance
to the nest was the most important factor in differentiating between foraging and
random locations, and there was no tendency to select or avoid any cover type.
Owls did forage in agricultural fields, but I failed to find evidence of selection or
avoidance of fields recently treated with pesticides. A total of 92 eggs were
collected over 5 years. Egg contaminants were generally limited to the presence of
p,p'DDE, which fluctuated by 4 orders of magnitude among years, from 0.05 ug/g
to 33 ug/g fresh weight p,p'DDE. There was a general pattern of decline in egg
residues over time for individual birds. The levels of p,p'DDE I documented did not
appear to have any effect on either productivity or survival of adult females, nor
were they clearly related to diet. I modeled the effects of various pesticide exposure
impacts on demographic rates and determined that exposure rates based on field
data would lead to relatively minor declines in population growth rate. An elasticity
analysis of burrowing owl demographic parameters revealed a variable pattern, but
generally indicated that factors influencing anyone of the demographic parameters
of burrowing owls can have a substantial impact on population growth rate. / Graduation date: 2002
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Geology and geochemistry of the Little Walker Volcanic Center, Mono County, CaliforniaPriest, George R. 29 May 1979 (has links)
Detailed mapping and geochemical analysis of Oligocene to early
Pliocene volcanic rocks in the Little Walker volcanic center, Mono
County, California have revealed a complex eruptive history. After
eruption of widespread rhyolitic ash flows of the Valley Springs
Formation in the Oligocene, Miocene to early Pliocene volcanism of
the western Great Basin and northern Sierra Nevada was dominated by
eruption of calc-alkalic, andesitic lavas bearing abundant hydrous
mafic phenocrysts, and, thus, high H���O contents. These kinds of
calc-alkaline magmas are associated with most of the major epithermal
Au-Ag districts of the western Great Basin.
A highly potassic latitic pulse of volcanism occurred at the Little
Walker volcanic center about 9.5 m.y. ago during the ongoing calc-alkalic
activity. The latitic series is unusually enriched in K and
other incompatible elements, as well as Fe compared to the surrounding
calc-alkaline rocks. The latites have mineralogic evidence of
much lower H���O content than the calc-alkaline lavas; yet early latitic
magmas were rich enough in volatiles to produce very large, welded
ash-flow sheets (e.g., the Eureka Valley Tuff). Rapid evacuation of
the magma reservoir beneath the Little Walker center during the
ash-flow activity resulted in formation of the Little Walker caldera.
Intracaldera volcanism culminated with extrusion of viscous,
phenocryst-rich plug domes and coulees of transitionally calc-alkaline,
low-K latite lava of the Lavas of Mahogany Ridge. The low-K latite
series is severely depleted in all incompatible elements relative to
early latitic rocks and has mineralogic, geologic, and trace element
evidence of higher H���O content relative to early latites. Significant
phenocrystic hornblende, association with hydrothermal alteration,
and high Eu����� /Eu����� all suggest significant H���O concentration in the
low-K latite magmas. These rocks probably come from a source
region intermediate between that of the calc-alkaline and latite series.
Trace and major element data favor generation of latitic magmas
from a primitive mantle diapir. The diapir rose into a subduction
zone that was actively generating widespread calc-alkalic lavas
throughout the region from hydrous mantle and, possibly, lower
crustal sources. The latite magmas were drier and hotter than the
calc-alkaline magmas, but were also enriched in volatiles, particularly
CO���, and incompatible elements from their undepleted mantle
source. Rising latitic magmas may have gained additional incompatible elements by wall rock reaction and zone refining of
upper mantle and lower crustal rocks. Extensive qualitative trace
element evidence of crystal fractionation shows that incompatible
elements may have been further concentrated by variable amounts of
crystal settling. High-pressure (plagioclase-poor, pyroxene-rich)
fractionation of the early, dry latitic series produced low-Ca-Mg
latites with high Fe/Mg and A1���0��� but low Si0���. Low-pressure
(plagioclase rich) differentiation of the early latitic magmas produced
quartz latite ash flows with high Si0��� and moderate Fe/Mg, while low-pressure
differentiation of hydrous low-K latite magmas yielded
silicic low-K latite and quartz latite lavas with low Fe/Mg. More
extensive separation of olivine relative to pyroxenes at low pressures
and increased stability of subsilicic hydrous crystals and Fe-Ti oxides
in the hydrous magmas account for changes in differentiation trends
caused by Ptotal and PH���O variations.
Lack of giant welded ash-flow sheets in the hydrous calc-alkaline
series and common eruption of such ash flows from volcanic centers
with rather anhydrous magmas led to the conclusion that H���0/CO��� as
well as total volatile content are critical controls on the likelihood of
large scale, hot ash-flow eruptions. Giant, hot ash-flow sheets and
associated calderas are favored in magmas with low H���0/CO��� and
high total volatile content. Basaltic and latitic volcanism in areas of
thick sialic crust, where crystal fractionation is extensive are,
therefore, the best sources of giant ash-flow sheets.
H���0/CO��� and total volatile content were also critical controls
of the probability of hydrothermal ore deposition. Magmas with high
H���0/CO��� and moderate total volatile contents are most favored for
ore deposition, because such magmas tend to form mesozonal or
epizonal plutons rather than volcanic rocks. Plutonic crystallization
of hydrous magma will yield a fluid phase capable of transferring
incompatible metals and geothermal heat to ground water. If permeable
structures and rocks are present, as in a caldera, widespread
mineralization will be favored, but there may be no genetic relation
between ore-forming magmas and magmas which produce calderas. / Graduation date: 1980 / For master (tiff) digital images of maps contained in this document contact scholarsarchive@oregonstate.edu
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Computer simulation of a biomanagement system : the Mendocino County deer population in CaliforniaAnderson, Frank M. 04 January 1972 (has links)
Management of deer populations is directed toward multiple
objectives. Deer populations on public and private lands belong to the
public and thus management is a political process. Four components
for an effective management system for deer populations are identified.
These are the set of objectives relating to the resource, the set of
regulations which will achieve the objectives, knowledge of the
expected population response to alternative management strategies,
and a means of monitoring these responses to determine whether or
not the objectives are being achieved.
Deer provide benefits mainly through the associated recreational
opportunities and cause costs by interacting with land based economic
activities such as agricultural crop production and reforestation. At
certain times of the year deer may also compete with domestic
livestock for forage. Deer also cause significant costs through collisions
with automobiles on the highways.
The extent of these benefits and costs, and others, is related to
the biosystem through parameters such as the size and composition of
the population, the extent of the hunting kill, and so on. In this thesis
a computer simulation model of the Mendocino County, California,
deer population is presented. The population is modeled as a density
dependent birth and death process. Hunting strategies are potentially
the most flexible management tool. Thus the model is structured to
permit detailed examination of the response over time of the population
to alternative hunting strategies.
In California, a bucks-only hunting strategy has been followed
since about the turn of the century. This study demonstrates that the
bucks-only strategy neither effectively controls the size of the deer
population, nor does it provide for the greatest recreational opportunities.
The extent of the costs referred to above are directly related
to the size of the population and the consumptive recreational benefits,
that is those due to hunting, are directly related to the size of the
hunting kill. Experiments with the model show that population control
can be achieved and the hunting kill can be increased by a mixed buck
and antlerless deer hunting strategy. Other results show that the
computer simulation model can provide information about the biosystem
which is not otherwise available.
Simulation methods permit considerable insights into the operation
and control of complex biosystems where the status of the systems
is time dependent and the systems are influenced by uncontrollable
elements so that at best the outcomes resulting from particular
management actions are uncertain. The simulation model used in this
study is applicable to other deer populations and other wildlife species. / Graduation date: 1972
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A shipping crate from the 1865 California shipwreck Brother Jonathan: hardware from the Russell and Erwin Manufacturing CompanySowden, Carrie Elizabeth 16 August 2006 (has links)
In the summer of 2000, divers recovered a large shipping crate from the wreck of the Brother Jonathan, a steamboat that sank off of Crescent City, California on 30 July 1865. Ownership of the crate was taken over by the state of California and was sent to Texas A&MÂs Conservation Research Laboratory for excavation and conservation. As soon as work began, it became clear that the crate contained a shipment of a variety of hardware most likely destined for a general store as each of the artifacts discovered was found in high quantities. Also, there was a wide variety of artifacts discovered, tools, architectural pieces, food preparation, fur trapping, and personal items. The crate was shipped from San Francisco from the warehouse of the Russell and Erwin Manufacturing Company; however, its final destination is unknown. Records for this warehouse and for the boat were destroyed in the earthquake and fire of 1906, so the destination for these goods is purely speculative. Using information from the excavation of the crate and a historical analysis of the contents led to a plausible theory. After careful review, it seems most likely that the crate was intended for a general store in a small town with a rural customer base.
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A shipping crate from the 1865 California shipwreck Brother Jonathan: hardware from the Russell and Erwin Manufacturing CompanySowden, Carrie Elizabeth 16 August 2006 (has links)
In the summer of 2000, divers recovered a large shipping crate from the wreck of the Brother Jonathan, a steamboat that sank off of Crescent City, California on 30 July 1865. Ownership of the crate was taken over by the state of California and was sent to Texas A&MÂs Conservation Research Laboratory for excavation and conservation. As soon as work began, it became clear that the crate contained a shipment of a variety of hardware most likely destined for a general store as each of the artifacts discovered was found in high quantities. Also, there was a wide variety of artifacts discovered, tools, architectural pieces, food preparation, fur trapping, and personal items. The crate was shipped from San Francisco from the warehouse of the Russell and Erwin Manufacturing Company; however, its final destination is unknown. Records for this warehouse and for the boat were destroyed in the earthquake and fire of 1906, so the destination for these goods is purely speculative. Using information from the excavation of the crate and a historical analysis of the contents led to a plausible theory. After careful review, it seems most likely that the crate was intended for a general store in a small town with a rural customer base.
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The relationship of academic success and selected other factors to student use of library materials at College of the DesertHostrop, Richard Winfred, January 1966 (has links)
Thesis--University of California (Los Angeles). / Includes bibliographical references.
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Process adequacy : successful school districts model /Estrada, Isaac. January 2010 (has links)
Thesis (Ed.D.) -- California State University San Marcos ; University of California, San Diego, 2010. / Abstract: leaves xiii-xiv. Committee members: Jennifer Jeffries (chair), Mark Baldwin, Alan Daly. Includes bibliographical references (p. 173-177) Also issued online
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Rip current spacing in relation to wave energetics and directional spreading /Holt, Robert D. January 2003 (has links) (PDF)
Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Edward B. Thornton, Timothy Stanton. Includes bibliographical references (p. 59-62). Also available online.
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The fall transition off Central California in 2002 /O'Malley, Colleen M. January 2003 (has links) (PDF)
Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Curtis A. Collins, Mary L. Batteen. Includes bibliographical references (p. 79-80). Also available online.
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