The Lake Hodges Monster

Extracted from:
Geology and Mineral Resources
Of San Diego County, California
Compiled by F. Harold Weber, Jr.
1958-59
Base Map Adapted from Map of
San Diego County by California
State Division of Forestry 1957

Lake Hodges Area Mines

Map No. Name of claim, mine, or group Location Owner info Geology Remarks & Reference

416
Bly Stone Co. quarry Center of sec. 10, Tlls, R2W, SBM (proj.); about 4 ¹/2 miles south of Escondido, and 3/8 of a mile west of U.S. Highway 395 Undetermined (1958) Bly Stone Co., Los Angeles 1924 Large residual boulders of dark- gray granitic rocks (San Marcos gabbro.) Operated from 1921 to 1924. Small quarry. Known also as one of the two Bernardo quarries. Other is Van Deventer, which see. (Hoppin and Norman 50:4,6,7).

439 (W.E.) Van Denter (Daley Corporation) quarry Sec. 10(?), T13S, R2W, SBM (proj.); about 4 to 5 miles south of Escondido. (Exact location undetermined). Undetermined (1957) Dark gray ("black") granitic rocks (San Marcos gabbro). Known also as one of the two Bernardo quaries (other is Bly Stone Co. which see also). Reported by Tucker (1925) to be on south shore of Lake Hodges but could not be located by present writer in 1957. Operated from 1921 to 1925, mainly by Van Deventer. Daley Corporation produced some stone from this quarry in 1923. (Hoppin and Norman 50:4,7; Tucker 25:363-364).

Explanation of symbols used on map:
Jg - Cretaceous and older; Hypabyssal intrusive rocks associated with the metavolcanic rocks.
Granite to granodiorite porphyry and rhyolite and dacite.
Jmv - Cretaceous and older; Metavolcanic rocks.
Black Mountain volcanics of the La Jolla quadrangle and Santiago Peak volcanics to north; chiefly flows that most commonly range from rhyolite to andesite, with minor proportion of tuff layers, and sparse metasedimentary layers; Economic Significance: source of crushed and broken stone; contains deposits of pyrophyllite, clay, gold, copper, iron and arsenic.
Kgb - Cretaceous; Gabbroic rocks.
San Marcos and Cuyamaca gabbros and unnamed bodies; chiefly gabbro with minor proportions of norite and diorite; Economic Significance: source of dimension stone (black granite), most important host rock for gem-bearing pegmatite deposits, and contins deposits of nickel-cobalt-copper.
Kgr - Cretaceous; Granitic rocks, undivided.
Quartz diorite (tonalite), with minor granodiorite, and granite; Economic Significance: source of dimension stone, decomposed granite, and crushed and broken stone; contain deposits of gold, tungsten, gem minerals, feldspar, quartz, and molybdenum.
m - Cretaceous and older; Metasedimentary rocks, undivided.
In northwestern part of county mainly slate and argillite with minor quartzite: Bedford Canyon formation of Triassic age; in north-central, central, east-central, and south-central parts of county mainly schist and minor quartzite: Julian schist; in northeast and southeast parts of county mainly schist, with minor gneiss and quartzite, and sparse limestone and dolomite (ls); in Jacumba region contain abundant granitic pegmatite and plutonic bodies; Economic Significance: schist contains deposits of gold, tungsten, manganese and graphite; quartzite is source of dimension stone at one locality; limestone and dolomite are source of crushed stone.
Qal - Quaternary, recent; Alluvium.
River and stream bottom, valley fill, flood plain, fan, beach sand, swamp, and sand dune deposits; except swamp deposits, essentially silt, sand, gravel, and minor proportions of cobbles and boulders; Economic Significance: important source of sand and gravel.
Qt - Quaternary, Pleistocene; Terrace deposits and dissected alluvium.
Marine and non-marine; sand and gravel and minor proportion of cobbles and boulders; Economic Significance: minor source of sand and gravel.
Tes - Tertiary, Eocene; Sandstone, undivided.
Includes Torrey and Delmar sands in La Jolla quadrangle and unnamed units to north; as shown includes some Rose Canyon shale for short distance north of La Jolla quadrangle; Economic Significance: source of plaster and specialty sands.

Note: Also see the U.S. Department of Agriculture/Bureau of Chemistry and Soils 1929 Soil Map of the Lake Hodges area.

Map No.	Name of claim, mine, or group	Location	Owner info	Geology	Remarks & Reference
416	Bly Stone Co. quarry	Center of sec. 10, Tlls, R2W, SBM (proj.); about 4 ¹/2 miles south of Escondido, and 3/8 of a mile west of U.S. Highway 395	Undetermined (1958) Bly Stone Co., Los Angeles 1924	Large residual boulders of dark- gray granitic rocks (San Marcos gabbro.)	Operated from 1921 to 1924. Small quarry. Known also as one of the two Bernardo quarries. Other is Van Deventer, which see. (Hoppin and Norman 50:4,6,7).
439	(W.E.) Van Denter (Daley Corporation) quarry	Sec. 10(?), T13S, R2W, SBM (proj.); about 4 to 5 miles south of Escondido. (Exact location undetermined).	Undetermined (1957)	Dark gray ("black") granitic rocks (San Marcos gabbro).	Known also as one of the two Bernardo quaries (other is Bly Stone Co. which see also). Reported by Tucker (1925) to be on south shore of Lake Hodges but could not be located by present writer in 1957. Operated from 1921 to 1925, mainly by Van Deventer. Daley Corporation produced some stone from this quarry in 1923. (Hoppin and Norman 50:4,7; Tucker 25:363-364).