- Usage in publication:
-
- Carson Pass tonalite
- Modifications:
-
- Named
- Dominant lithology:
-
- Tonalite
- AAPG geologic province:
-
- Sierra Nevada province
Summary:
Shown in geologic sketch map of western half of Markleeville 15-min quadrangle, Alpine Co., CA, in area near Carson Pass. [Age not stated.]
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Carson Pass Tonalite*
- Modifications:
-
- Age modified
- Geochronologic dating
- AAPG geologic province:
-
- Sierra Nevada province
Summary:
Carson Pass Tonalite of Parker (1961) shown on geologic map of Freel and Dardanelles Further Planning Area, Alpine and El Dorado Cos, CA. Described as dark-bluish-gray, brownish-gray weathering, medium-grained hornblende-biotite granodiorite to quartz diorite. Intrudes Burnside Lake Adamellite of Parker (1961) in southeast area of study. K-Ar age on biotite yielded 88.7 +/-2 Ma (Evernden and Kistler, 1970). Using I.U.G.S. constants calculated age is 90.9 +/-2 Ma. Age on map given as Late Cretaceous.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Carson Pass Tonalite*
- Modifications:
-
- Geochronologic dating
- AAPG geologic province:
-
- Sierra Nevada province
Summary:
K-Ar age on biotite from Carson Pass Tonalite yielded 90.9 +/-2 Ma. Sample collected at 38 deg 41' 41"N, 119 deg 59' 03"W, Alpine Co, CA.
Source: GNU records (USGS DDS-6; Menlo 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 ([ ]).