Year: 2013
Type: dissertation
Abstract: Passive margins, despite being of major economic importance, are poorly understood, especially at depth. The Texas Gulf Coast Margin was chosen for this study due to its relatively short cratonic-ocean distance. Ps receiver functions were generated from data from the X4 array, a 300 km passive array with 23 stations extending from Matagorda Island, a barrier island on the coast of Texas, to Johnson City, TX, a northwest-southeast profile crossing two major geologic zones of interest, the Gulf Coast Plains and the Edwards Plateau/Llano Uplift. Data were processed at 0.4, 0.8, and 1.6 Hz. A Vp/Vs method utilizing constant ratio stacks (CRS) was used to find a correct S-velocity model, showing improvement over assigning flat Vp/Vs of 1.8 or √3 assuming a Poisson’s solid. Several features were identified in the stacked data, including an area of anomalous upper mantle or lower crust that may be related to the Triassic and Jurassic rifting events with what appears to be a delaminated segment and a strong negative zone beneath transitional crust possibly due to serpentinization during rifting or subduction as part of the Ouachita orogeny.
Author: M. Knuppel
Language: English
Topic: Seismic Waves and Analysis
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
Funder: Texas Tech University
OpenAlex ID: W2284846861