Discrimination of eolian and pyroclastic-surge processes in the generation of cross-bedded tuffs, Jemez Mountains volcanic field, New Mexico

Journal Article · Wed May 01 00:00:00 EDT 1991 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1991)019<0465:DOEAPS>2.3.CO;2· OSTI ID:5667575

Smith, G A; Katzman, D ^[1]

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1. Univ. of New Mexico, Albuquerque (USA)

Discrimination of pyroclastic deposits emplaced by volcanic processes and reworked pyroclastic sediments is a primary objective of studies in volcaniclastic strata. Cross-bedded tuffs of both eolian and pyroclastic-surge origins are identified within the late Miocene Peralta Tuff Member of the Bearhead Rhyolite, in north-central New Mexico. Distribution, paleoflow directions, grain-size characteristics, and depositional structures permit discrimination of these similar facies. Eolian tuffs exhibits structures diagnostic of eolian sands, are relatively well sorted, and lack both the fine ash and coarse lapilli and bombs typically found in surge deposits. Discrimination between eolian reworked and primary surge pyroclastic deposits is critical for volcanic hazard studies near modern volcanoes and for correct interpretation of proximity to vents in ancient volcaniclastic sequences.

• OSTI ID: 5667575
• Journal Information: Geology; (USA), Vol. 19:5; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
JEMEZ MOUNTAINS
STRATIGRAPHY
DEPOSITION
DETECTION
DISTRIBUTION
FORECASTING
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
GRAIN SIZE
HAZARDS
MIOCENE EPOCH
NEW MEXICO
ORIGIN
SAND
TUFF
VOLCANIC REGIONS
VOLCANIC ROCKS
VOLCANISM
WIND
CENOZOIC ERA
CRYSTAL STRUCTURE
DEVELOPED COUNTRIES
FEDERAL REGION VI
GEOLOGIC AGES
IGNEOUS ROCKS
MICROSTRUCTURE
MOUNTAINS
NORTH AMERICA
ROCKS
SIZE
TERTIARY PERIOD
USA
580000* - Geosciences