- Usage in publication:
-
- Kroenke Granodiorite*
- Modifications:
-
- Named
- Dominant lithology:
-
- Quartz monzonite
- Quartz diorite
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Named for exposures west of Kroenke Lake, the type area, Gunnison Co, CO; also known in Eagle basin of Chaffee Co, CO (both in Southern Rocky Mountain region). Consists of quartz diorite, granodiorite, and quartz monzonite in a sharply discordant body. Underlies drainage area of Pine Creek, North Cottonwood Creek, Texas Creek, and a small pluton in Ptarmigan Creek. Ranges in composition from quartz monzonite to quartz diorite. Is mostly white, light gray, or buff, and fine to medium grained, commonly foliated, and contains single grains and wisp-like clusters of biotite. The granodiorite contains swarms of amphibolite inclusions in some places. The plagioclase is calcic oligoclase or sodic andesine. Biotite is commonly altered to chlorite, and is intergrown with apatite, epidote, sphene, magnetite, and allanite. Intrudes Denny Creek Granodiorite Gneiss along many miles of contact. Is post-tectonic. Is younger than Browns Pass Quartz Monzonite. Assigned to Precambrian.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Kroenke Granodiorite*
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Present in several bodies in central Sawatch Range and adjoining lower slopes of Mosquito Range, in Southern Rocky Mountain region. Is trondhjemitic in composition. Listed with granitic rocks of circa 1,700 m.y. (Precambrian X) age group.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Kroenke Granodiorite*
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Is one of nine formally named lithodemic units assigned to the Early Proterozoic Routt Plutonic Suite (a new name). Is in a pluton about 130 km (sq) or 50 mi (sq), and in a few smaller outlying bodies; extends from west edge of Sawatch Range to mountain front northeast of Canon City in the Southern Rocky Mountain region, CO. Is a trondhjemitic and leucocratic rock that intrudes Denny Creek Granodiorite. Is white to buff, fine to medium grained, and foliated to massive. Biotite is sparse. Swarms of amphibolite present locally.
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 ([ ]).