The biodiversity of most marine communities is more or less dependent on continuous invasions from sources with greater richness. These ongoing, natural invasions have become greatly augmented by ship traffic in numerous estuaries and harbors where the native biota has been diminished or lost due to habitat destruction and pollution....
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ef-
fects of invasive species at the community level (Rick-
lefs 1987, Karlson et al. 2004, Witman et
The primary goal of this study is to assess the impact of a subduction component
added to the mantle wedge beneath the Oregon Cascades to the composition and fO2 of
primitive Cascade basalts. Olivine-hosted melt inclusions from compositionally diverse
basalts across the Cascade arc (~100 km) are utilized in an...
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provided by Rick Conrey and Dave Sherrod. In
addition, Carl Thornber’s help with the Mount St. Helens
Understanding continental crust formation and modification is a fundamental and longstanding geologic problem. Influx of mantle-derived basaltic magma and partial melting of the crust are two ways to drive crustal differentiation. This process results in a low density upper crust and denser, more refractory lower crust, creating significant and vastly...
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great insight into the results. Rick Conrey
(Washington State University) was essential in obtaining
Volcanic and sedimentary deposits of the Mount Jefferson area (MJA) record a fourmillion-year
history of arc-related volcanism related to the subduction of the Juan de Fuca plate
beneath North America. 171 mapped stratigraphic units over an area of 150 km² reveal four
periods of volcanic activity resulting in diverse composition...
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geochemical investigation of Mount Jefferson on which this study is based. Rick has been
constantly
A sequence of volcanic, volcaniclastic, and epiclastic deposits from Oligocene to Recent age are exposed in the region from Lake
Simtustus to Madras in central Oregon. The epiclastic sediments of the Oligocene John Day Formation are unconformably overlain by two flows of the middle Miocene Columbia River Basalt Group. The...
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Portland General
Electric Company.
I would like to thank Debbie Cannon, Rick Conrey, Tom Dill,
Glenn
Neogene rocks of the Deschutes basin include the middle Miocene
Columbia River Basalt Group and Simtustus Formation, and late Miocene
to early Pliocene Deschutes Formation. Assignment of Prineville
chemical-type flows to the Grande Ronde Basalt of the Columbia River
Basalt Group is based upon correlation of these lavas from their...
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State University under
the direction of Dr. Peter Hooper and supported by RHOBWIP. Isotopic
age
The Central Oregon High Cascade Range is an anomalously mafic segment of the
Cascade Arc due to ongoing intra-arc extension, which allows most magmas to traverse
the crust without stalling and evolving to more evolved compositions. North Sister, a
composite volcano in this arc segment, has produced a seemingly monotonous...
In the future, Earth will be warmer, precipitation events will be more extreme, global mean sea level will rise, and many arid and semiarid regions will be drier. Human modifications of landscapes will also occur at an accelerated rate as developed areas increase in size and population density. We now...
The interaction of magma with continental crust at convergent margins is fundamental to
understanding if and how continents grow. Isotopic and elemental data constrain the
progressive stages of development of the magmatic underpinnings of the long-lived
Aucanquilcha Volcanic Cluster (AVC), situated atop the thick continental crust of the
central Andes...
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. For help in various labs throughout my time, I’d like to
thank Dale Burns, Frank Mazdab, Rick Conrey