Tectonic implications of newly documented early( ) through late Paleozoic age strata, Black Rock Desert region, northwest Nevada
- Univ. of Houston, TX (United States)
Early Paleozoic to Pennsylvanian age strata are exposed in several of the Paleozoic arc sequences of the western United States cordillera where they form depositional basement for thick volcanic and volcaniclastic sequences of Permian age. New work in the Pine Forest range, BRD, however, indicates that this range contains a previously unrecognized, but extensive and structurally intact section of metamorphosed middle (and early ) Paleozoic through Late Permian age strata. This section has been dated paleontologically and radiometrically, and consists of the following (protolith descriptions in ascending stratigraphic order): (1) quartzo-feldspathic sedimentary and mafic volcanic rocks of probable early Paleozoic and/or Devonian age, and mafic volcanic rocks of probable Devonian age; (2) generally deep marine, chert/argillite/quartz-rich clastic rocks of post-late Devonian( ) to Late Mississippian age; (3) shallow marine carbonate of middle Carboniferous age; (4) volcanic and volcaniclastic rocks of Early Pennsylvanian age; (5) shallow marine limestone and volcaniclastic rocks of Early Permian( ) age. This stratigraphic succession documents a history that is very similar to that recorded in other Paleozoic arc sequences of the western United States cordillera, including a record of early Paleozoic to Devonian( ) quartzose sedimentation and volcanism, Mississippian deep marine siliciclastic sedimentation, some renewed volcanism in Pennsylvanian time, and generally shallow marine to emergent conditions in Pennsylvanian to Early Permian time. A significant difference between the Paleozoic record in the BRD and that in other arc sequences further west, however, is the much greater thicknesses of volcanic rocks in the latter areas. This relation suggests that the BRD lay in a back-arc position relative to the main axis of Paleozoic arc volcanism.
- OSTI ID:
- 5210719
- Report Number(s):
- CONF-9103128--
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:2; ISSN AABUD; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
580000* -- Geosciences
AGE ESTIMATION
ARID LANDS
DEPOSITION
DESERTS
DEVELOPED COUNTRIES
FEDERAL REGION IX
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
IGNEOUS ROCKS
METAMORPHISM
NEVADA
NORTH AMERICA
PALEONTOLOGY
PALEOZOIC ERA
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
TECTONICS
USA
VOLCANIC ROCKS
VOLCANISM