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Upper Mantle Structure of the Southern U.S. Continental Margin From Teleseismic Traveltime Tomography
Author(s) -
Netto Alden,
Pulliam Jay
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl085482
Subject(s) - geology , terrane , craton , mantle (geology) , seismology , rift , crust , continental margin , seismic tomography , laurentia , tectonics , geophysics , paleontology
The southern U.S. continental margin records a rich tectonic history spanning ~1.35 Ga, including two complete Wilson cycles. Due to a thick sediment cover, the paucity of local seismicity, and sparse seismic instrumentation, the tectonomagmatic evolution of this passive margin remains uncertain. The recent USArray seismic network offers an opportunity to address unresolved issues by imaging the crust and upper mantle. Direct teleseismic P and S traveltimes recorded at ~1,600 stations are mapped into 3‐D velocity perturbations. P and S tomography models, although generated independently, are broadly consistent, with a strong correlation between anomaly patterns in the sublithospheric mantle and known crustal features. Fast mantle velocities correspond to the Laurentia Craton and Llano and Grenville terranes, while intracratonic rift systems and Paleozoic arc terranes are marked by slow anomalies in the upper mantle.