Author: Xiaohua Peng
Publisher:
ISBN:
Category : Snake River Plain (Idaho and Or.)
Languages : en
Pages : 16
Get Book Here
Book Description
Teleseismic receiver functions are used to estimate the crustal structure beneath a 36-station, 500-km-long, NW oriented linear array centered on the eastern Snake River Plain and crossing the Yellowstone hotspot swell 250 km SW of Yellowstone. Structure derived previously for this region from wide-angle reflection data is used as an initial model, and this structure explains most features observed in our receiver functions. Based on a combination of forward and inverse modeling, our data require several modifications to the initial structure: (1) Moho depth is ~42 km beneath most of the Snake River Plain, shallows to ~37 km to either side, and thickens abruptly to ~47 km beneath SW Wyoming; (2) a midcrustal layer interpreted previously as a ~9-km-thick gabbroic sill is flat topped across the entire ~90 km width of the Snake River Plain; and (3) a low-velocity layer is found beneath and southeast of the Snake River Plain, which probably is partially molten lower-most crust. Using the seismic structure of the crust to estimate the crustal load upon the mantle, and assuming local isostasy, we calculate that mantle beneath the Yellowstone swell is approximately uniformly as buoyant as 12-million-year-old ocean mantle, and more buoyant than the adjacent Wyoming mantle by an amount equivalent of ~1.5 km of elevation. The transition between these regions of greatly different mantle occurs across a major Paleozoic boundary that now separates the Basin and Range from the Rocky Mountains.
Author: Catherine Annen
Publisher: Geological Society of London
ISBN: 9781862392588
Category : Science
Languages : en
Pages : 300
Get Book Here
Book Description
Magmas are subject to a series of processes that lead to their differentiation during transfer through and storage within the Earth's crust. The depths and mechanisms of differentiation, the crustal contribution to magma generation through wall-rock assimilation, the rates and timescales of magma generation, transfer and storage, and how these link to the thermal state of the crust are subject to vivid debate and controversy. This volume presents a collection of research articles that provide a balanced overview of the diverse approaches available to elucidate these topics, and includes both theoretical models and case studies. By integrating petrological, geochemical and geophysical approaches, it provides new insights to the subject of magmatic processes operating within the Earth's crust, and reveals important links between subsurface processes and volcanism.
Author: Katrina Robb Settles
Publisher:
ISBN:
Category : Plate tectonics
Languages : en
Pages : 468
Get Book Here
Book Description
Author: P. K. Link
Publisher: Geological Society of America
ISBN: 9780813723532
Category : Science
Languages : en
Pages : 326
Get Book Here
Book Description
Author: Derek Leigh Schutt
Publisher:
ISBN:
Category : Earth (Planet)
Languages : en
Pages : 14
Get Book Here
Book Description
Seismic V P , V S , and V P /V S structure is imaged across the Yellowstone hot spot swell, including the hot spot track where magmatism occurred at the eastern Snake River Plain 610 m.y. B.P. Data are teleseismic P and S travel time delays that have been corrected for the well-understood upper mantle anisotropy and crustal structure. Amplitude variations in the imaged structures are 6.2%, 11.2%, and 8% for V P , V S , and V P /V S , respectively. The dominant structure is a zone which extends beneath the Snake River Plain to a depth of 190 km that is high in V P /V S and low in V P and V S . The physical state of the upper mantle is inferred by assuming isostasy, using the volume of melt segregated from the mantle that is inferred from estimates of magma addition to the crust, and using relations that scale changes in temperature, partial melt fraction and composition to density. Specifically, we infer that the low-velocity mantle beneath the Snake River Plain is partially molten up to 1.0%, and the high-velocity Yellowstone swell mantle away from the Snake River Plain is 80 K cooler and 5% depleted in basaltic component. The imaged large seismic velocity variations occur under near isothermal conditions.
Author: Bill Bonnichsen
Publisher: Idaho Geological Survey
ISBN:
Category : Geology, Structural
Languages : en
Pages : 508
Get Book Here
Book Description
Author: Joel L. Pederson
Publisher: Geological Society of America
ISBN: 081370006X
Category : Science
Languages : en
Pages : 532
Get Book Here
Book Description
Author: Jeffrey Lee
Publisher: Geological Society of America
ISBN: 0813700213
Category : Science
Languages : en
Pages : 232
Get Book Here
Book Description
Compiled for the 2011 joint meeting of the GSA Rocky Mountain and Cordilleran Sections, this field guide provides an introduction to some of the remarkable geology of the Rocky Mountain and Cordillera regions.
Author: C. Prodehl
Publisher:
ISBN:
Category : Earth
Languages : en
Pages : 88
Get Book Here
Book Description
A reinterpretation of seismic-refraction measurements made from 1961 to 1963 and a comparison with the crustal structure of central Europe.
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 562
Get Book Here
Book Description
