- Usage in publication:
-
- Green Valley tonalite*
- Modifications:
-
- Named
- Dominant lithology:
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- Tonalite
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Named first used by Miller (1937) for its characteristic development in Green Valley in extreme southeastern part of San Luis Rey 30' quad, San Diego Co, CA. Underlies an area of about 68 sq mi in quad. Is gray medium-grained tonalite, uniform in character. Resembles Bonsall tonalite but lacks abundant streaked inclusions. Chemical analyses included in report. Intrudes Triassic sedimentary rocks, Jurassic volcanic rocks, and San Marcos gabbro. Intruded by Woodson Mountain granodiorite (new). Map legend shows age as Cretaceous.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Green Valley tonalite*
- Modifications:
-
- Areal extent
- Age modified
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Green Valley tonalite underlies about 50 sq mi in Cuyamaca Peak 15' quad, San Diego Co, CA. Is older than Bonsall tonalite and younger than Cuyamaca gabbro. Age given as Late Cretaceous locally in this quad.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Green Valley Tonalite*
- Modifications:
-
- Geochronologic dating
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Pg. 10, geologic time scale (inside front cover). Green Valley Tonalite. Sample from approx. Lat. 33 deg. 05 min. 15 sec. N., Long. 116 deg. 58 min. 00 sec., San Pasquel 7.5-min quadrangle, San Diego County, California, yielded a Pb-alpha age of 90 +/-10 Ma (zircon) [Cretaceous], indicating probable time of emplacement. Age calculated using decay constants of Steiger and Jager, 1977 (Earth Planet. Sci. Letters, v. 36, p. 359-362).
Source: Publication.
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 ([ ]).