Keywords and Phrases
Crustal Thickness; Joint Inversion; Receiver Function; Structure; Surface Wave Dispersion; Vp/Vs
"In spite of numerous geophysical investigations have been conducted in southeastern United States, the structure and evolution of the crust and lithospheric mantle remain controversial due the thick sedimentary covers atop the crust of the coastal plains there. In this study, we use data from 186 broadband seismic stations belonging to the USArray Transportable Array to construct a 3-D shear wave velocity model for the southeastern United States for the top 180 km by a joint inversion of Rayleigh wave phase velocity dispersion and receiver functions. Our results show a clear spatial correspondence with major surficial geological features. A prominent low velocity anomaly observed in the depth range of 0 to 25 km beneath the eastern Gulf Coastal Plain suggests the existence of thick sediments atop the crystalline crust. The eastern side of the southern Appalachian Mountains is characterized by low crustal Vp/Vs, thin crust, and slow lower crustal velocities, which may be caused by lower crustal delamination followed by relamination. Beneath the Osceola intrusive complex located at the central Suwannee Terrane, our results show low Vp/Vs measurements and seismically fast lower crust, which are attributable to eclogites in the lower crust. The Grenville Province and a narrow zone to its east possess relatively higher Vp/Vs values comparing with the surrounding areas, which can be attributed to mafic intrusion associated with crustal extension in the recently recognized eastern arm of the Proterozoic Midcontinent Rift. According to the isostasy theory, we estimate the density variations from the resulting velocity anomalies in the top 180 km, which indicate that contributions from density anomalies in greater depths are required to reach isostatic balance"--Abstract, page iv.
Gao, Stephen S.
Liu, Kelly H.
Geosciences and Geological and Petroleum Engineering
Ph. D. in Geology and Geophysics
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Crustal and upper mantle structure beneath the southeastern United States from joint inversion of Rayleigh wave dispersion and receiver functions
ix, 186 pages
© 2021 Qiuyue Yang, All rights reserved.
Dissertation - Open Access
Yang, Qiuyue, "Crustal and upper mantle structure beneath the southeastern United States from joint inversion of Rayleigh wave dispersion and receiver functions" (2021). Doctoral Dissertations. 2988.