3 3 22' 30" 11 7 07' 30" 3 3 30' 00" 11 7 07' 30" 3 3 22' 30" 11 7 00' 00" 3 3 30' 00" 11 7 00' 00" STATE OF CALIFORNIA - GRAY DAVIS GOVERNOR THE RESOURCES AGENCY - MARY NICHOLS, SECRETARY FOR RESOURCES DEPARTMENT OF CONSERVATION - DARRYL YOUNG, DIRECTOR Prepared in cooperation with the U.S. Geological Survey DIVISION OF MINES AND GEOLOGY JAMES F. DAVIS, STATE GEOLOGIST Topographic base by U.S. Geological Survey 7.5’ Pechanga Quadrangle Polyconic projection, contour interval 20 feet, dotted lines 10 fee t. A. Hanley, J.B. and Janhs, R.H., 1950 unpublished geological maps of the Pala and Rincon pegmatite districts, San Diego County, California: Un- published U.S. Geological Survey mapping (scale 1:24,000). This mapping was used with slight modification for the basement rock geology throughout the central portion of the quadrangle. B. Irwin, W.P. and Greene, R.C., 1970, Studies related to wilderness primi- tive areas, Agua Tibia, California: U.S. Geological Survey Bulletin 1319-A, 19 p., map scale 1:48,000. This mapping was used with slight modification for the basement rock geology in the east-central part of the quadrangle. C. Jahns, R.H., and Wright, L.A., 1951, Gem- and lithium-bearing pegmatites of the Pala district, San Diego County, California: California Division of Mines and Geology Special Report 7-A, 72 p., map scale 1:18,000. This mapping was used with slight modification for the pegmatites and adjacent bedrock geology in the Pala gem district. D. Kennedy, M.P., 1977, Recency and character of faulting along the Elsinore fault zone in southern Riverside County, California: California Division of Mines and Geology Special Report 131, 12 p., map scale 1:24,000. This mapping was used with slight modification for the northern half of the quadrangle. E. Kennedy, M.P., 2000, New 1:24,000-scale geologic mapping completed between July 1999, and June 2000. F. Larsen, E.S. Jr., 1948, Batholith and associated rocks of Corona, Elsinore and San Luis Rey quadrangles, southern California: Geological Society of America Memoir 29, 182 p., scale 1:125,000. This mapping was useful in depicting regional contacts between major plutons but the very small scale does not allow direct use of these contacts at 1:24,000 . D,E B,D,E,F B,E,F A,E A,D,E C,E E,F A,E REFERENCES Contact between map units. Fault - dashed where inferred, dotted where concealed. Arrow and number indicate direction and angle of dip of fault plane. Anticline - solid where accurately located; dotted where concealed. Strike and dip of inclined sedimentary beds. Strike and dip of overturned sedimentary beds. Strike and dip of foliation. Strike of vertical foliation. Landslide - arrows indicate principal direction of movement. Air photo lineament - Mostly joints and minor faults. Pegmatite dike. Closed depression . 65 18 18 1 8 Syncline - solid where accurately located; dotted where concealed . MAP SYMBOLS Qyf Qvof Qw Qya Qoa Qvoa Qyc Qoc Qvoc Qds Qols Qp Tt Qa Kr Kp Kat Kgd Kgdf Kt Kgb Kgbf KJq KJs T v Pliocene Miocene Pleistocene Holocene QUATERNARY CRETACEOUS JURASSIC CENOZOIC MESOZOI C TERTIAR Y CORRELATION OF MAP UNITS Qw Qa Qy a Qyc Qy f Qoa Qo c Qo f2 Qol s Qvo a Qvoc Qvo f Q p Qd s Tt Tv K r K p Kgd Kgd f K t Kg b Kgb f K J KJ q KJs Qof2 Kat DESCRIPTION OF MAP UNITS MODERN SURFICIAL DEPOSITS - Sediment that has been recently transported and deposited in channels and washes, on surfaces of alluvial fans and alluvial plains, and on hillslopes and in artificial fills. Soil-profile development is non- existant. Includes: Active channel and wash deposits (late Holocene) - Unconsolidated to locally poorly unconsolidated sand and gravel deposits in active washes of streams. Active alluvial flood plain deposits (late Holocene) - Unconsolidated to locally poorly unconsolidated sand and gravel deposits in active alluvial flood plains. YOUNG SURFICIAL DEPOSITS - Sedimentary units that are slightly consolidated to cemented and slightly to moderately dissected. Alluvial fan deposits typically have high coarse:fine clast ratios. Younger surficial units have upper surfaces that are capped by slight to moderately developed pedogenic-soil profiles. Includes: Young alluvial flood plain deposits (Holocene and late Pleistocene) - Mostly poorly consolidated, poorly sorted, permeable flood plain deposits. Young alluvial fan deposists (Holocene and late Pleistocene) - Mostly poorly consolidated and very poorly sorted sand, gravel, cobble and boulder deposits in young alluvial fans. Young colluvial deposits (Holocene and late Pleistcene) - Mostly poorly consolidated and poorly sorted slope wash and stream deposits. OLD SURFICIAL DEPOSITS - Sediments that are moderately consolidated and slightly to moderately dissected. Older surficial deposits have upper surfaces that are capped by moderate to well-developed pedogenic soils. Includes: Older alluvial flood plain deposits (Pleistocene, younger than 500,000 years) - Mostly moderately well consolidated, poorly sorted, permeable flood plain depostits. Older colluvial deposits (Pleistocene, younger than 500,000 years) - Mostly moderately well consolidated, poorly sorted slope wash and stream deposits. Older fan deposits (Pleistocene, younger than 500,000 years) - Mostly poorly consolidated fan, debris flow and talus deposits. Clasts possess a moderately well developed clay coating but are otherwise fresh. Older landslide deposits (Pleistocene, younger than 500,000 years) - Landslide slump and rock fall depostits. VERY OLD SURFICIAL UNITS - Sediments that are slightly to well consolidated to indurated, and moderately to well dissected. Upper surfaces are capped by moderate to well-developed pedogenic soils. Includes: Very old alluvial flood plain deposits (early Pleistocene) - Mostly well-indurated, poorly sorted, semi-permeable clay and sand flood plain deposits. Very old colluvial deposits (early Pleistocene) - Mostly well-indurated, poorly sorted, hillslope, clay and sand colluvial deposits. Very old alluvial fan deposits (early Pleistocene) - Mostly very well-indurated, reddish-brown, sand and cobble, early Pleistocene aluvial fan deposits. Pauba Formation (early Pleistocene) - Light-brown moderately well-indurated, extensively crossbedded, channeled and filled sandstone and siltstone that contains occassional intervening cobble-and -boulder conglomerate beds. Dripping Springs Formation (early Pleistocene) - Pebble, cobble and boulder fanglomerate in a reddish-brown, poorly consolidated, poorly sorted sandstone matrix. BEDROCK UNITS Temecula Arkose (Pleistocene) - Pale greenish-yellow, well-indurated, medium- and coarse- grained sandstone with thin interstratified beds of fine-grained, tuffaceous sandstone, siltstone, and claystone. Pebble and cobble conglomerate interbeds composed of locally derived basement rock clasts are also common and range in thickness from a few centimeters to a meter or more. Basalt (Miocene) - Dark-gray and black, fine-grained basalt. Granodiorite of Rainbow (Cretaceous) - Leucocratic hornblende-biotite granodiorite; medium- to coarse-grained, massive. Granodiorite of Pala (Cretaceous) - Leucocratic granodiorite and migmatite; fine- to medium-grained. Gabbro of Agua Tibia Mountain (Cretaceous) - Hornblende gabbro; medium- to coarse-grained, massive to foliate. This gabbro often contains minor biotite and quartz (quartz bearing gabbro). Granodiorite undivided (Cretaceous) - Mostly hornblende-biotite granodiorite; medium- to coarse-grained. Granodiorite undivided fault part (Cretaceous) - Leucocratic hornblende-biotite granodiorite that has been extensively sheared along the Elsinore fault zone. Tonalite undivided (Cretaceous) - Mainly hornblende-biotite tonalite; coarse-grained, light gray. Gabbro undivided (Cretaceous) - Mosltybiotite-hornblende-hypersthene gabbro; coarse-grained, dark gray, massive. Gabbro undivided fault part (Cretaceous) - Mosltybiotite-hornblende-hypersthene gabbro that has been extensively sheared along the Elsinore fault zone. Quartzite and quartz conglomerate (Cretaceous and Jurassic) - Mostly quartzite, quartz conglomerate and meta-arkose. Schist with minor amphibolite and marble (Cretaceous and Jurassic) - Mostly quartz-mica-schist, quartz-mica amphibole schist, and feldspathic amphibole schist. Metavolcanic and metasedimentary rocks undivided (Cretaceous and Jurassic) - Low grade (greenschist facies) rocks that are in part coeval with and in part older than the Cretaceous plutonic rocks they lie in contact with. KJ KJs KJs Qa Qw Kr Kr Qoc Qyc Qoa Qa Qa Qyc Qw This geologic map was funded in part by the U.S. Geological Survey National Cooperative Geologic Mapping Program, STATEMAP Award no. 99HQAG0134. Copyright 2000 by the California Department of Conservation Division of Mines and Geology. All rights reserved. No part of this publication may be reproduced without written consent of the Division of Mines and Geology. "The Department of Conservation makes no warranties as to the suitability of this product for any given purpose." c San Onofre Bluff Margarita Peak Fallbrook Temecula Pechanga Pala Bonsall Morro Hill Valley Center San Clemente Escondido Las Pulgas Canyon Pacific Ocean 1 5 74 5 78 76 15 71 79 79 Oceanside San Clemente Laguna Beach Encinitas Mission Viejo San Juan Capistrano Murrieta Temecula Fallbrook San Marcos Escondido Dana Point GN 240 MILS 1 3 0 0 2 1 MIL MN UTM GRID AND 1988 MAGNETIC NORTH DECLINATION AT CENTER OF SHEET 1/ 2 W I L D O M A R F A U L T Z O N E E L S I N O R E F A U L T Z O N E W O L F V A L L E Y F A U L T Z O N E Qp Kgb+Kgd Tv Qa Qw Qp Qp Qp Qp Tv Tt Tv Qols Kgb+Kgd Qya+Qyc Tt Qp Qyc Qp Tt Qya Kgd Qp Qp Qoa Tt Qvoa Qya Qoa Tt Qyc Kgb Qya Qds Kat Tt Qvoa Qyc Kr Qyc Kgd Qyc Qw Qoa Qoa Qoa Kat Tt Qyc Qw Tt Qyf Qyc Qyc Qyc Qds Qyc KJ Kr KJ Qp Kat Tt Qp Kat Qoc Kgb Kgd Kgd Kat Kgdf Kgdf Kr Kat Qvoc Kgbf Qvoc Kgdf Kat Qvoc Kr Qvoc Kgd Kgb Qvoc Kgb Kr KJq Kp Kp Qvof Kgd Kgb KJq KJq Kgb Kp Qvof Kgb Kgdf Kat Qof2 Qof2 Qof2 Qols Kp Qw Qvof Kp Kgb Kgb Qof2 Kgb Qvof Kat Kgb Qof2 Kp Qof2 Qa Qp Qoa Qoa Qya Qoa Qoa Kr Qya Kr Qyc Qp Qa Qw Qyf Qa Qw Qw Kg b 85 80 80 80 80 75 70 65 70 75 85 60 80 80 70 75 75 70 70 75 85 85 80 80 80 85 85 80 75 75 85 85 70 60 80 80 60 30 65 75 80 70 60 70 85 72 70 78 85 63 65 50 60 60 45 60 65 70 50 40 80 80 80 80 72 80 35 3 2 3 4 2 2 2 2 5 2 5 3 3 5 5 3 5 50 60 3 3 3 5 5 25 25 5 40 75 70 50 65 75 80 20 20 15 15 10 5 20 10 30 40 35 35 25 40 35 35 45 10 3 80 5 3 5 5 35 40 40 50 30 45 50 40 35 50 40 25 25 35 35 50 30 50 20 20 25 20 30 25 30 25 45 30 25 25 25 25 40 45 25 25 25 10 25 30 25 50 45 60 30 35 50 35 40 25 35 30 75 85 60 70 55 80 80 75 75 80 75 80 DEPARTMENT OF CONSERVATION Division of Mines and Geology GEOLOGIC MAP OF THE PECHANGA 7.5' QUADRANGLE SAN DIEGO AND RIVERSIDE COUNTIES, CALIFORNIA: A DIGITAL DATABASE VERSION 1.0 By Michael P. Kennedy 1 Digital Database by Brad L. Nelson 2 and Rachel M. Hauser 2 2000 1. California Division of Mines and Geology, Los Angeles, CA 2. U. S. Geological Survey, Riverside, CA Quartz Syenite Quartz Monzonite Quartz Monzodiorite Syenite Monzonite Monzodiorite Granite Alkali-feldspar Granite Tonalite Diorite Syenogranite Granodiorite Monzo g ranite Quartz Diorite 90 65 35 10 5 20 60 Q Q A P 60 20 5 60 Classification of plutonic rock types (from IUGA, 1973, and *Streckeisen, 1973). A, alkali feldspar; P, plagioclase feldspar; Q, quartz. *Streckeisen, A.L., 1973, Plutonic rocks--Classification and nomenclature recommended by the IUGA Subcommission on Systematics of Igneous Rocks: Geotimes, vol.18, pp.26-30.