Crustal and Upper Mantle Structure Beneath the Southeastern United States from Joint Inversion of Receiver Functions and Rayleigh Wave Dispersion
Abstract
Using data from 186 stations belonging to the USArray Transportable Array, a three-dimensional shear wave velocity model for the southeastern United States is constructed for the top 180 km by a joint inversion of receiver functions and Rayleigh wave phase velocity dispersion computed from ambient noise and teleseismic earthquake data. The resulting shear wave velocity model and the crustal thickness and Vp/Vs (κ) measurements show a clear spatial correspondence with major surficial geological features. The distinct low velocities observed in the depth range of 0-25 km beneath the eastern Gulf Coastal Plain reflect the thick layer of unconsolidated or poorly consolidated sediments atop the crystalline crust. The low κ (1.70-1.74) and slow lowermost crustal velocities observed beneath the eastern Southern Appalachian Mountains (including the Carolina Terrane and Inner Piedmont) relative to the adjacent Blue Ridge Mountains and Valley and Ridge can be interpreted by lower crustal delamination followed by relamination. The Osceola intrusive complex in the central Suwannee Terrane has similar crustal characteristics as the eastern Southern Appalachian Mountains and thus can similarly be attributed to crustal delamination/relamination processes. The Grenville Province and adjacent areas possess relatively high κ values which can be attributed to mafic intrusion associated with crustal extension in a recently recognized segments of the eastern arm of the Proterozoic Midcontinent Rift.
Recommended Citation
Q. Yang et al., "Crustal and Upper Mantle Structure Beneath the Southeastern United States from Joint Inversion of Receiver Functions and Rayleigh Wave Dispersion," Journal of Geophysical Research: Solid Earth, vol. 126, no. 10, article no. e2021JB021846, Wiley, Oct 2021.
The definitive version is available at https://doi.org/10.1029/2021JB021846
Department(s)
Geosciences and Geological and Petroleum Engineering
Keywords and Phrases
Crustal Structure; Eclogitization; Mantle Structure; Rayleigh Wave Dispersion; Receiver Function; Southeastern U.S.
Geographic Coverage
Southeastern United States
International Standard Serial Number (ISSN)
2169-9356; 2169-9313
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2021 Wiley, All rights reserved.
Publication Date
01 Oct 2021
Comments
The study was partially supported by the American Chemical Society under grant PRF-60281-ND8, and the U.S. National Science Foundation under award 1919789.