Tectonic setting of blueschist and island-arc terranes of west-central Baja California, Mexico
Diverse oceanic rocks exposed in west-central Baja California (Mexico) are assigned to three shallowly dipping tectonic units. The lower plate is a subduction complex consisting of regionally metamorphosed blueschists and divided into structurally and petrologically distinct subterranes. The upper plate consists of Triassic-Lower Cretaceous arc rocks and overlapping mid-Cretaceous turbidites. A fault-bounded serpentinite-matrix melange between lower and upper plate rocks contains blueschist, eclogite, amphibolite, and variably serpentinized mafic and ultramafic blocks. Lower plate blueschists were metamorphosed in the late Early Cretaceous and uplifted along shallowly dipping normal faults during conditions of steady-state subduction. Exotic blocks of blueschist, eclogite, and amphibolite are derived from a cryptic terrane or terranes, record varied P-T-t histories, and were uplifted via tectonic emplacement or diapiric rise of serpentinite along the normal faults.
- Research Organization:
- Stanford Univ., CA (USA)
- OSTI ID:
- 7183333
- Journal Information:
- Geology; (United States), Journal Name: Geology; (United States) Vol. 16:7; ISSN GLGYB
- Country of Publication:
- United States
- Language:
- English
Similar Records
The P-T-t history of blocks in serpentinite-matrix melange, west-central Baja California
Geochronology of blueschists from west-central Baja California and the timing of uplift in subduction complexes
Related Subjects
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
AMPHIBOLITES
CONTINENTAL MARGIN
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
GROUND UPLIFT
LATIN AMERICA
METAMORPHIC ROCKS
METAMORPHISM
MEXICO
NORTH AMERICA
ROCKS
SCHISTS
STRATIGRAPHY
TECTONICS