No description available.

Data collected by personnel of the Geophysics Group at Oregon State University and the Instituto Oceanografico of the Direccion General dé Oceanografia are used to construct a free-air anomaly map for the central part of the Pacific continental margin of Mexico, which shows the gravity expression of major structural features in the region. Specific features are the Middle America and Rivera trenches intersected by a possible extension of the Rivera Fracture Zone, and the Ulloa Trough on the western side of Baja California. Of particular importance are gravimetric minimums with no bathymetric expression observed east of the Tres Marias Islands, southeast and northwest of the Tamayo Fracture Zone, and as extensions of the bathymetrically mapped series of en echelon faults within the Gulf of California. A geophysical model cross section constructed along a profile southeast of the Tres Marias Islands indicates a continental type crust east of the islands with a Moho depth of 13 km at the base of the Tres Marias Scarp and dipping toward the continent. The structure at the transition zone between oceanic and continental crust suggests active subduction of the oceanic crust in the past followed by a period of shear or strike-slip motion. The thickness of the sediments along the cross section and east of the Tres Marias Islands reaches 1.5 km. / Graduation date: 1981

Gravity, magnetic and seismic data indicate that the oceanic crust is 9.7 km thick west of the Continental Borderland. The top of the mantle is about 12 km deep under the Borderland, and deepens to 27 km beneath the Peninsular Ranges of Baja California. The mantle is about 20 km below the surface of the Imperial Valley and deepens to 27 km under the area east of the Imperial Valley. The age of the youngest detectable remnant magnetic anomaly over the oceanic crust is about 16.5 million years at 21.3°N Lat. and decreases to the south. A magnetic anomaly expected along the continuation of the San Benito Fault Zone is not detected by this study. A gravity low along the base of the Patton Escarpment is at least partially the result of a buried trench-like depression. In the vicinity of 31.3°N Lat., 119.3°W Long. this depression is filled with 2 km of sediments. The geophysical and geological data are interpreted as indicating a 6 km thick section of Franciscan rocks that extends from the west edge of the Borderland to the Coronado Escarpment. Magnetic data suggest that an ophiolite may be present within or on top of the Franciscan rocks. Several of the ridges in the Borderland have cores of high density rocks which are interpreted as intrusives. The area just south of the San Clemente basin has an anomalously thin upper crust. The gross crustal structure of this region is comparable to the Imperial Valley region and may represent a former site of crustal rifting which occurred when the East Pacific Rise was subducted under this part of the North American plate. North of the Santo Tomas Fault Zone are several basins filled with more than 3 km of sediments, but south of this fault zone the sediment cover is discontinuous and generally less than 2 km thick. / Graduation date: 1978

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 117-134).

Graduation date: 1981

Thesis (PhD)--University of South Australia, 2001.

Thesis (doctorat d'etat ès sciences naturelles)--Université Pierre et Marie Curie, Paris, 1976. / "No d'enregistrement au C.N.R.S., 12.305." Includes bibliographical references (p. 117-137).

No description available.

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.