- Usage in publication:
-
- Bonanza latite
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Latite
- AAPG geologic province:
-
- San Luis basin
Summary:
Pg. 21-63. Bonanza latite. Usually gray, grayish black when fresh, sometimes brown, fine-grained, with phenocrysts of feldspar and often biotite. Is country rock of most of Bonanza district, Saguache County, southern Colorado. Age is Tertiary.
Source: US geologic names lexicon (USGS Bull. 896, p. 231).
- Usage in publication:
-
- Bonanza latite*
- Modifications:
-
- Revised
- AAPG geologic province:
-
- San Luis basin
Summary:
As applied in the San Luis basin in this report, is a Tertiary unit that includes all lavas between the Rawley andesite and Squirrel Gulch latite (hornblende biotite latite of Patton, 1916). Includes two members, lower and upper members, which are about 1,000 ft thick. Use represents redefinition of Patton's Bonanza in that the upper member is an added unit. Source is unknown. Is contemporaneous with Hayden Peak latite. Mapped (geologic map) in east-central and northeast parts of district.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Bonanza Tuff*
- Modifications:
-
- Geochronologic dating
- AAPG geologic province:
-
- San Luis basin
Summary:
Bonanza Tuff lies in San Luis basin area of Colorado. Is derived from the Bonanza caldera, one of oldest calderas in the eastern part of San Juan volcanic field. Relationship of Bonanza caldera to other calderas of the field indeterminate at present time. Bears an age of more than 27.8 m.y.
Source: Modified from 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 ([ ]).