The displaced eugeoclinal rocks in the El Paso Mountains and northern Mojave Desert: A Triassic sliver
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Geology
- Univ. of Kansas, Lawrence, KS (United States). Dept. of Geology
Many workers have drawn attention to the displaced eugeoclinal rocks in the northern Mojave Desert and El Paso Mountains and their importance in models for the development of an active continental margin in the western Cordillera. Existing models can generally for either strike-slip juxtaposition or thrust emplacement. New field data, U-Pb zircon geochronology, and isotopic data for metasedimentary rocks and plutons in the northern Mojave Desert and El Paso Mountains shed light on the timing and mechanism of emplacement of the eugeoclinal allocthon. The observations and data above indicate that Early Triassic plutons in the northern Mojave Desert came through oceanic lithosphere but later Jurassic plutons intercepted continental lithosphere. The authors suggest a model where eugeoclinal rocks were deposited on oceanic crust which was initially brought southward along a strike-slip fault and later thrust eastward over the cratonal assemblage. Permian thrusting is incompatible with their data and observations. Intrusion of lower Triassic strata by Early Triassic plutons in the Lane Mountain area permits some Early Triassic thrusting but the oceanic affinity of the plutons implies that thrusting did not involve continental lithosphere.
- OSTI ID:
- 5019456
- Report Number(s):
- CONF-9305259-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALIFORNIA
GEOLOGIC DEPOSITS
PLATE TECTONICS
ISOTOPE DATING
PETROGENESIS
PLUTONIC ROCKS
CONTINENTAL MARGIN
GEOLOGIC FAULTS
GEOLOGIC HISTORY
GEOLOGIC MODELS
ISOTOPE RATIO
LEAD ISOTOPES
OCEANIC CRUST
TRIASSIC PERIOD
URANIUM ISOTOPES
ZIRCON
ACTINIDE ISOTOPES
AGE ESTIMATION
DEVELOPED COUNTRIES
EARTH CRUST
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
IGNEOUS ROCKS
ISOTOPES
MESOZOIC ERA
MINERALS
NORTH AMERICA
PETROLOGY
ROCKS
SILICATE MINERALS
TECTONICS
USA
580000* - Geosciences