Crustal structure of accreted terranes in southern Alaska, Chugach Mountains and Copper River Basin, from seismic refraction results

G. S. Fuis; E. L. Ambos; Walter D. Mooney; N.I. Christensen; E. Geist

doi:10.1029/90jb02316

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Crustal structure of accreted terranes in southern Alaska, Chugach Mountains and Copper River Basin, from seismic refraction results

G. S. Fuis·E. L. Ambos·Walter D. Mooney·N.I. Christensen·E. Geist

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Abstract

Seismic refraction data were collected along a 320-km-long "transect' line in southern Alaska, crossing the Prince William, Chugach, Peninsular, and Wrangellia terranes, and along several shorter lines within individual terranes. Velocity structure in the upper crust (less than 9-km depth) differs among the four terranes. In contrast, layers in the middle crust (9- to 25-km depth) in some case extend across projected terrane boundaries. The top of a gently north dipping sequence of low- and high-velocity layers (5.7-7.8 km/s), more than 10 km thick, extends from near the surface in the southern Chugach terrane to more than 20-km depth beneath the southern Peninsular terrane. This sequence, truncated by the suture between the Prince William and Chugach terranes, is interpreted to be an underplated "terrane' made up of fragments of the Kula plate and its sedimentary overburden that were accreted during subduction in the late Mesozoic and/or early Tertiary, during or between times of accretion of the Prince William and Chugach terranes.

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Journal of Geophysical Research Article

Source-reported bounding extent: 58.722598828043374° to 63.430860212678105° latitude; -155.126953125° to -140.625° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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G. S. Fuis, E. L. Ambos, Walter D. Mooney, N.I. Christensen, E. Geist. 2012-09-20. Crustal structure of accreted terranes in southern Alaska, Chugach Mountains and Copper River Basin, from seismic refraction results. https://doi.org/10.1029/90jb02316

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