- Usage in publication:
-
- Tres Piedras granite
- Modifications:
-
- Named
- Dominant lithology:
-
- Granite
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Named for exposures around town of Tres Piedras, secs 22 and 23, T28N, R9E, Tres Piedras quad, Rio Arriba Co, NM in the Southern Rocky Mountain region. No type locality designated. Includes granite formerly mapped as Tusas granite. Is a pink, flesh-colored or reddish-orange, faintly- to well-foliated, fine- to medium-grained, quartz-microcline-albite-biotite-muscovite granite. Is younger than the Maquinita granodiorite and older than the Ritito conglomerate (both new units in this report). Is of Precambrian age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Tres Piedras Granite*
- Modifications:
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- Revised
- Age modified
- Dominant lithology:
-
- Quartz monzonite
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Tres Piedras Granite of Barker (1958) restricted to foliated granite of 1,700 Ma (Proterozoic Y) age. Type area designated in shallow prospect pits about 100 m west of road in NE1/4 sec 23, T28N, R7E on west side of Tusas Mountain in Rio Arriba Co, NM in Southern Rocky Mountain region. Intrudes interlayered Precambrian metavolcanic and metasedimentary rocks and is covered locally by Tertiary sediments. Is a pink to pale-orange, medium-grained quartz monzonite.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Tres Piedras Granite*
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Intruded metavolcanic and metasedimentary rocks of the Tusas Mountains, Rio Arriba Co, Southern Rocky Mountain region, assigned to the Moppin Metavolcanics and Burned Mountain Metarhyolite (both revised and adopted) about 1,700 m.y. ago. Age changed from Proterozoic X to Early Proterozoic.
Source: GNU records (USGS DDS-6; Denver GNULEX).
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 ([ ]).