Stratigraphic relations and lithologic variations in the Jemez volcanic field, New Mexico

Journal Article · Mon Feb 10 04:00:00 EST 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB091iB02p01763· OSTI ID:5875734

Gardner, J N; Goff, F; Garcia, S; Hagan, R C

Over 100 radiometric dates and recent detailed geologic mapping allow some refinements of the stratigraphic relations of major units and generalization of temporal lithologic variations in the Jemez volcanic field. Volcanism had begun in the area by about 16.5 Ma with episodic eruptions of alkaline basalts. By 13 Ma, alkaline volcanism had been replaced with eruptions of more voluminous olivine tholeiite. High-silica rhyolite, derived from melts of lower crust, also was erupting by about 13 Ma. Basalt and high-silica rhyolite continued to be erupted until about 7 and 6 Ma, respectively, but effusions of dominantly andesitic differentiates of basalt that began as early as about 12 Ma volumetrically overshadowed all other eruptive products between 10 and 7 Ma. From 7 to 13 the dominant erupted lithology was dacite, which appears to have been generated by mixing of magmas whose compositions are approximated by earlier andesites and high-silica rhyolites. Less than 4--3 Ma volcanism was dominated by eruption of rhyolitic tuffs.

• Research Organization: Earth and Space Sciences Division, Los Alamos National Laboratory, New Mexico
• OSTI ID: 5875734
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 91:B2; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580202* -- Geophysics-- Volcanology-- (1980-1989)
CALDERAS
FEDERAL REGION VI
GEOLOGY
JEMEZ MOUNTAINS
LITHOLOGY
MEASURING INSTRUMENTS
MOUNTAINS
NEW MEXICO
NORTH AMERICA
RADIATION DETECTORS
RADIOMETERS
STRATIGRAPHY
USA
VOLCANIC REGIONS