Geophysics And Petrology Of The Deep Crust And Upper Mantle

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These results agree with observed properties of the lower crust from geophysical
measurements (Jiracek and others, 1979; Seager and Morgan, 1979; Baldridge
and others, 1984) and suggest that crustal granulite may have a major influence
on observed properties of the crust in reactivated intracontinental rifts.
COLORADO PLATEAU Techniques.--Crustal xenolith suites from Moses Rock
dike and Mule Ear diatreme were sampled in order to compare observed seismic
velocity ...


Author: Erik A. Hanson
Publisher: Infobase Publishing
ISBN: 1438106645
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The uplift of the Colorado Plateau was crucial to the formation of the Grand
Canyon, as discussed in chapter 1, but some aspects of the early Colorado
Plateau have been confusing for researchers. The Colorado Plateau was at sea
level during the interval between 100 and 70 million years ago, but the crust
beneath the plateau is presently too thick to be consistent with a sea-level
elevation. The crust of the Colorado Plateau is presently about 28 miles (45 km)
thick, and essentially, ...

The Earth S Crust

Author: John G. Heacock
Publisher: American Geophysical Union
ISBN: 0875900208
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transition zone beneath areas surrounding the Basin and Range province to the
north and the east are very similar to the Sierra Nevadas; beneath the Snake
River Plains (function 4) to the north; and beneath the middle Rocky Mountains (
function 6) and the Colorado plateau (function 7) to the east a 40 to 45 km thick
crust is separated from the upper mantle by a 5 to 10 km thick transition zone. A
similar relationship is true for the southern Rocky Mountains (function 8) and the
adjacent ...

Geologic Studies In The Basin And Range Colorado Plateau Transition In Southeastern Nevada Southwestern Utah And Northwestern Arizona 1995

Author: Florian Maldonado
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The most primitive erupted magmas appear to be represented by the high-Nb
mafic rocks. However, based on their relatively low Nd and high Sr isotopic
compositions, even this magma type is likely to have been contaminated by
crustal materials. Less contaminated magmatic compositions are represented by
lava flows in the central part of the Markagunt Plateau, where we have identified
more primitive compositions having "Sr/*Sr=0.704 and eNd= 0 (Nealey and
others, 1993).

Sedimentary Cover North American Craton U S

Author: L.L. Sloss
Publisher: Geological Society of America
ISBN: 0813754496
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Although the lithosphere has been affected, the crust of the Colorado Plateau has
remained sufficiently unmodified during the Phanerozoic that we can consider it
part of the craton. Thus, despite the fact that it is virtually ... Numerous crustal
seismic investigations show anomalously thick crust, roughly 45 km, beneath the
Colorado Plateau, thinning to roughly 30 km in the Basin and Range Province
and 30 to 35 km beneath the Rio Grande Rift. Moho depths as shallow as 25 km
are ...

Amplitude Studies Of Cocorp Deep Seismic Reflection Profiling Data From The Basin And Range And Colorado Plateau

Author: James Roger Mayer
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zones in deep reflection data and should be estimated as a standard part of any
interpretational procedure. INTR0DUCTI0N Fundamental differences in
lithospheric structure are apparent between the Colorado Plateau and adjacent
Basin and Range province. For example, the Colorado Plateau is characterized
by a 40 km thick crust and heat flow of 1.25 HFU (Keller et al., 1979; Bodell and
Chapman, 1982), whereas crust in the Basin and Range is only 30 km thick with
heat flow of ...

Geophysical Framework Of The Continental United States

Author: Louis Charles Pakiser
Publisher: Geological Society of America
ISBN: 081371172X
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The crust of Roller's (1965) P-wave velocity model at Hanksville in the Colorado
Plateau (Figs. 1; 3, model 6) is 41 km thick, which is about the same as the 43-km
-thick crust of Hill and Pakiser (1966) and Braile and others (1982) in the Snake
River Plain (Fig. 3, models 4 and 5). However, the velocity distribution within the
crust is distinctly different. The upper crust (P-wave velocity, 5.2 km/sec) is only
about 10 km thick in the Snake River Plain, as compared with the 27-km-thick
upper ...

Geology Of North America An Overview

Author: Albert W. Bally
Publisher: Geological Society of America
ISBN: 0813754453
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Colorado Plateau. The history of the Colorado Plateau is intimately related to that
of the extensional province. Both regions experienced regional uplift of as much
as 3 km after about 24 Ma (Lucchitta, 1979; Young, 1979, Epis and others, 1980),
but unlike the Basin and Range province, the structural integrity of the Colorado
Plateau as a discrete tectonic block was maintained. Surface-wave studies of the
Plateau indicate that it has a 45-km-thick crust (Keller and others, 1979) ...