An integrated analysis of controlled- and passive source seismic data

Eva-Maria Rumpfhuber, University of Texas at El Paso

Abstract

This dissertation consists of two parts, which include a study using passive source seismic data, and one using the dataset from a large-scale refraction/wide-angle reflection seismic experiment as the basis for an integrated analysis. The goal of the dissertation is the integration of the two different datasets and a combined interpretation of the results of the "Continental Dynamics of the Rocky Mountains" (CD-ROM) 1999 seismic experiment. I have determined the crustal structure using four different receiver function methods using data collected from the northern transect of the CD-ROM passive seismic experiment. The resulting migrated image and crustal thickness determinations confirm and define prior crustal thickness measurements based on the CD-ROM and Deep Probe datasets. The new results show a very strong lower crustal layer (LCL) with variable thickness beneath the Wyoming Province. In addition, I was able to show that it terminates at 42° latitude and provide a seismic tie between the CD-ROM and Deep Probe seismic experiments so they represent a continuous N-S transect extending from New Mexico into Alberta, Canada. This new tie is particularly important because it occurs close to a major tectonic boundary, the Cheyenne belt, between an Archean craton and a Proterozoic terrane. The controlled-source seismic dataset was analyzed with the aid of forward modeling and inversion to establish a two-dimensional velocity and interface model of the area. I have developed a picking strategy, which helps identify the seismic phases, and improves quality and quantity of the picks. In addition, I was able to pick and identify S-wave phases, which furthermore allowed me to establish an independent S-wave model, and hence the Poisson's and Vp/Vs ratios. The final velocity and interface model was compared to prior results, and the results were jointly interpreted with the receiver function results. Thanks to the integration of the controlled-source and receiver function results, I was able to construct a well-constrained structural model and tectonic interpretation that shows the structural framework of the transition from the Wyoming craton to the north across the Cheyenne belt suture zone to the Proterozoic terranes on the south. The interpretation that crustal-scale crocodile structures are present provides an explanation for the south dip of the Cheyenne belt in the upper crust and the north-dipping slab in the mantle. The very distinct crustal structures north and south of the suture zone are clearly shown in our model.^

Subject Area

Geology|Geophysics

Recommended Citation

Rumpfhuber, Eva-Maria, "An integrated analysis of controlled- and passive source seismic data" (2008). ETD Collection for University of Texas, El Paso. AAI3310669.
http://digitalcommons.utep.edu/dissertations/AAI3310669

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