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...
Biological nitrogen fixation (BNF) is a key ecological process that can restore nitrogen (N) lost in wildfire and shape the pace and pattern of post-fire forest recovery. To date, there is limited information on how climate and soil fertility interact to influence different pathways of BNF in early forest succession....
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E094-064-A1
Stephanie Yelenik, Steven Perakis, and David Hibbs. 2013. Regional constraints to
The Summer Coon intrusive center is located seven miles
north of Del Norte, Colorado, on the eastern edge of the San Juan
Mountains. The intrusive center is the core of a dissected calcalkaline
composite volcano of middle Oligocene age. The Summer
Coon rocks belong to the Conejos Formation which is...
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States affected by crustal extension (Lipman and
others, 1970).
According to Steven and Epis (1968
Four multicyclic complex calderas and smaller ignimbrite shields located within the Altiplano Puna Volcanic Complex of the Central Andes (APVC) erupted 13000 km³ of magma within the last 11 Ma. One of the largest and most complex of these is the Cerro Guacha Caldera. Ar-Ar age determinations and paleomagnetic directions...
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(Steven and Lipman, 1976; Lipman 2007), and Toba (van Bemmelen, 1939; Chesner, 2011).
These efforts
The current model for gamma ray bursts (GRBs) assumes that internal shocks are responsible for the emission of gamma-rays. Internal shocks occur when the fast expanding shell collides with the slowly expanding shells. The light curve of a GRB depends on the initial state and the expanding speed of the...
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. Campana, A. Gomboc, J. Japelj, M.G. Bernardini, S.
Covino, S. D. Vergani, R. Salvaterra, and G
Symbiotic N₂-fixing tree species can accelerate ecosystem N dynamics through decomposition feedbacks via both direct and indirect pathways. Direct pathways include the production of readily decomposed leaf litter and increased N supply to decomposers, whereas indirect pathways include increased tissue N and altered detrital dynamics of non-fixing vegetation. To evaluate...
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Accelerates Ecosystem
Nitrogen Cycling
Steven S. Perakis,1* Joselin J. Matkins,2,3 David E. Hibbs,2
and
The southern half of the upper Nehalem River basin contains
the most complete section of lower to middle Tertiary marine sedimentary
and volcanic rocks in northern Oregon. Determination of
stratigraphic relationships of six formations, and their depositional
environments and provenance is the chief objective of this paper.
More than 75...
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. Snavely, Jr. , Robert J. Deacon and Herbert G.
Schlicker are greatly appreciated. Dr. Jerry L. Glenn
The oldest rocks of the Sturgill Peak area are herein named the
grassy slope phyllites, and are of Permian (?) age. They are
divided into a phyllitic member, consisting of complexly folded and
highly sheared phyllites and phyllitic cherts, and a limestone member,
containing sheared limestone, silicified limestone, and chert....
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, Idaho
AN ABSTRACT OF THE THESIS OF
STEVEN JOHN SKURLA for the MASTER OF SCIENCE
(Name) (Degree)
in