Lithospheric Structure of the Sabine Uplift From Joint Modeling of Receiver Functions and P Autocorrelations
Description:
Joint modeling of receiver functions and teleseismic autocorrelations is an effective tool for modeling crustal structure, and is particularly useful in regions without regional seismicity and in the deep basins. P receiver functions contain energy converted from P-type to S-type at abrupt impedance contrasts, such as a sediment-basement contact and Moho, while vertical autocorrelations contain P wave reverberations from the same interfaces. Modeling both together provides better constraints on crustal structure than do receiver functions alone, since P wave reverberation delay times are sensitive to interface depth and Vp, while Ps delay times are sensitive to interface depth and Vp/Vs.
In this study we perform joint modeling to determine crustal structure in the vicinity of the Sabine Uplift, a feature at the Texas-Louisiana Border that has been shown to have a deeper Moho than the Ouachita Mountains to the north and the Gulf of Mexico to the south. It has been interpreted to be either an accreted Gondwanan terrane or island arc that collided with the North American craton during the Ouachita Orogeny. Further, the Sabine “Island”, located to the south of the Uplift, is characterized by anomalously low velocities and low densities in lower crust or upper mantle.
P receiver functions in the region show at least two clear interfaces, likely the sediment-basement contact and Moho, while the vertical autocorrelations typically show the sediment-basement contact. Waveform modeling of the vertical autocorrelations and P receiver functions in the area indicates basin depths of ~2-8 km depth and Moho depths of ~30-42 km. P receiver functions computed from stations in the southern portion of the region show at least one additional interface, which could mark the lower bound of a rift pillow that has been proposed as a result of previous gravity modeling.
Session: Earth’s Structure From the Crust to the Core [Poster]
Type: Poster
Date: 4/18/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Benjamin Sadler
Student Presenter: Yes
Invited Presentation:
Authors
Benjamin Sadler Presenting Author Corresponding Author benjamin_sadler1@baylor.edu Baylor University |
Jay Pulliam jay_pulliam@baylor.edu Baylor University |
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Lithospheric Structure of the Sabine Uplift From Joint Modeling of Receiver Functions and P Autocorrelations
Category
Earth’s Structure From the Crust to the Core