The western margin of the Rio Grande rift in northern New Mexico: An aborted boundary?
- Purdue Univ., West Lafayette, IN (United States); and others
The northwestern margin of the Espanola basin, part of the Rio Grande rift in northern New Mexico, is characterized by a zone >17 km wide of oblique-slip faults that off-set upper Paleozoic and Mesozoic strata of the eastern Colorado Plateau from Eocene and younger sedimentary rocks of the rift. Along this margin, a reasonably complete section of pre- and synrift Tertiary sediments is exposed. Combined interpretations of seismic reflection, seismic refraction, gravity, and geologic data acquired along a profile perpendicular to this boundary define the geometry of faulting, possible rotation of sedimentary units, and stratigraphy of rift fill. Vertical separation on the westernmost major fault, assumed to be the bounding fault between the rift and the Colorado Plateau, is <500 m; separation on other faults in the zone is <200 m. Thus the northwestern part of the Espanola basin ({open_quotes}Abiquiu embayment{close_quotes}) is a shallow platform rather than a deep rift basin. The embayment is separated from the main Espanola basin by the east-northeast-striking Embudo transfer fault, which appears to act as the northern bounding fault of the main basin. 42 refs., 10 figs., 3 tabs.
- OSTI ID:
- 577430
- Journal Information:
- Geological Society of America, Bulletin, Journal Name: Geological Society of America, Bulletin Journal Issue: 12 Vol. 106; ISSN BUGMAF; ISSN 0016-7606
- Country of Publication:
- United States
- Language:
- English
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