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Geologic Units: Toltec
  • Usage in publication:
    • Toltec andesite member
  • Modifications:
    • Original reference
  • Dominant lithology:
    • Andesite
  • AAPG geologic province:
    • San Juan basin
Publication:

Muehlberger, W.R., Adams, G.E., Longgood, T.E., Jr., and St. John, B.E., 1960, Stratigraphy of the Chama quadrangle, northern Rio Arriba County, New Mexico, IN Beaumont, E.C., and Read, C.B., eds., Guidebook of the Rio Chama Country [New Mexico and Colorado]: New Mexico Geological Society Field Conference Guidebook, no. 11, p. 93-102.


Summary:

Pg. 100. Toltec andesite member of Treasure Mountain rhyolite. Name credited to E.L. Trice (unpub. thesis). Chiefly black perlitic vitric porphyritic andesite. Lowermost member; fills valleys cut into underlying Conejos quartz latite. Thickness 0 to 50 feet. Underlies Lagunitas clastic member (new). Age is late Miocene.
Type locality not stated. Present in northeastern part of Brazos Peak quadrangle, northwestern NM.

Source: US geologic names lexicon (USGS Bull. 1200, p. 3910).


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

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