- Usage in publication:
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- Mount Princeton quartz monzonite*
- Modifications:
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- Revised
- AAPG geologic province:
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- Eagle basin
- Piceance basin
Summary:
Authors follow Stark and Barnes (1935) in adopting Mount Princeton (rather than Princeton) quartz monzonite. Only the southern part of the batholith which has a maximum diameter of about 20 mi is present in the northern part of Garfield quad, Gunnison Co, CO in the Piceance basin and Chaffee Co, CO in the Eagle basin. Many small outlying bodies and dikes mapped. Is fresh-appearing, gray, medium-grained quartz monzonite and difficult to distinguish from the pre-Cambrian granite that it intrudes. Texture is even-granular through slightly porphyritic. Has white, gray-pink feldspar, glassy quartz, biotite, green hornblende, and a few brown crystals of sphene. Is older than Mount Antero granite. Is younger than Mount Pomeroy quartz monzonite. Assigned a Paleocene? to Oligocene? age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Mount Princeton Quartz Monzonite*
- Modifications:
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- Age modified
- AAPG geologic province:
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- Eagle basin
Summary:
Considered to be older than Wall Mountain Tuff, which has a radiometric age of 35-36 m.y. and therefore assigned an Eocene? to Oligocene? age. [A general statement--no specific locality designated.] Located in Chaffee Co, CO in the Eagle basin.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Mount Princeton batholith*
- Modifications:
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- Age modified
- AAPG geologic province:
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- Eagle basin
Summary:
Previously considered Eocene? to Oligocene?. Dated as an Oligocene intrusive unit in the southern Sawatch Range in the Eagle basin.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Mount Princeton Quartz Monzonite*
- Modifications:
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- Age modified
- AAPG geologic province:
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- Eagle basin
Summary:
Intrusive rocks about 60 km southeast of Aspen in Garfield Co, CO, Piceance and Eagle basins, of Mount Princeton batholith is probably mid-Tertiary, late Eocene and early Oligocene in age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Mount Princeton Quartz Monzonite*
- Modifications:
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- Geochronologic dating
- Revised
- AAPG geologic province:
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- Eagle basin
- Piceance basin
Summary:
Ages of 34.9 +/-1.0 to 41.1 +/-0.9 m.y. K-Ar method on biotite and hornblende and of 34.4 +/-0.3 to 37.1 +/-0.3 39Ar/40Ar on hornblende, biotite, and orthoclase have been obtained on the Mount Princeton Quartz Monzonite. Petrologic description. Geologic map. Mapped in Chaffee Co, CO in the Eagle basin and into Gunnison Co, CO in the Piceance basin. A small granite stock in the Hoffman Park area formerly mapped as part of the Mount Princeton is removed from the Mount Princeton and designated Hoffman Park Granite (new). Ages of 34.5 +/-0.8 to 36.6 +/-1.1 m.y. (biotite) and 34.8 +/-1.7 to 41.1 +/-1.2 (hornblende) K-Ar method and 34.4 +/-0.3 (biotite) and 35.4 +/-0.3 m.y. to 37.1 +/-0.3 (hornblende) 39Ar/40Ar method. Geologic maps. Oligocene age.
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 ([ ]).