Marine geophysical data from the continental margin of Baja
California and the Gulf of California, and geological and geophysical
data from the Baja California Peninsula and mainland Mexico, outline
the major geologic and tectonic features of the Baja California
Peninsula and the surrounding areas from 24.5° N. Lat. to 27.5° N.
Lat. A crustal and subcrustal cross section consistent with observed
gravity and magnetic anomalies, and constrained by seismic refraction
stations and the mapped surface geology shows major variations of
density and magnetization in these areas. A geologic interpretation of
the cross section indicates the rocks of the Pacific continental margin
are composed of unconsolidated and semiconsolidated sediments.
Tertiary sedimentary rock, metamorphic rock of Franciscan type, and
continental crystalline rock probably corresponding to the Peninsular
Range batholith. The depth to mantle under the Baja California
Peninsula is postulated to be 20 km. In the Gulf of California a section
of low-density mantle beginning at a depth of 11 km is necessary
to fit the observed gravity values and accounts for the low seismic
velocities associated with the mantle in the Gulf. The correlation
between the observed magnetic anomalies on the Pacific continental
margin of the Baja California Peninsula and the theoretical magnetic
anomalies expected from a spreading center shows that the youngest
identifiable remanent anomaly on the Pacific side of south central
Baja California is anomaly 3' formed at 6 my B.P. The remanent
magnetic anomalies extend 50 km landward from the western edge of
the continental slope. / Graduation date: 1978
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29204 |
| Date | 14 November 1977 |
| Creators | Coperude, Shane Patrick |
| Contributors | Couch, Richard W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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