Occurs in Elsinore, San Jacinto, and Ramona 30' quads. Underlies most of Lakeview Mountain in Elsinore quad, Riverside Co, CA. Lakeview Mountain tonalite replaces name Lakeview quartz-hornblende diorite of Dudley (1935) and Lakeview tonalite of Merriam (1941). Is uniform rather coarse-grained nearly white rock with scattered black plates of biotite and stout prisms of hornblende. In contact with Bonsall tonalite; character of contact indicates Bonsall tonalite intrudes Lakeview Mountain tonalite but the two probably not very different in age. Map legend gives age as Cretaceous.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
Lakeview Mountain tonalite found in north-central part and on western edge of Santa Ysabel 15-min quadrangle, San Diego County, California. Appears to be younger than Green Valley tonalite. Contacts with rocks other than Green Valley poorly exposed; hence, no definite age determination could be made.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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