jamul final2 - conservation.ca.gov · jamul_final2.ai author: cgutierr created date: 3/23/2006...
TRANSCRIPT
�
�
���
��
��
�
�
�
�
�
�
����
�
��
�
��� �
�
��
�
��
�� � � �
�
81
86
83
78
82
7079
7580
72
7
7
5
7
5
7
10
45
8
5
30
82
74
80
87
85
81
75
77
80
87
70
5
78
81
65
6
Qya
Qw
Qya
Qya
Qya
Qya
Qoa
Qya
Qoa
Qoa
To
To
Tmv
Tsd
Qya
To
QoaQoa
Qvoa
Tsd
Tsd
Tsd
Tsd
Tmv
Tmv
Tmv
Qvoa
Tsd
Tmv
Qls?
Qls?
Qya
Qya
Qoa
Qls
Tsd
Qvoa
To
Qya
Tmv
Qls?
Kgt
Kgt
Kgt
Kgt
Kgt Kgt
Kgt
Kgt
Kgt
Kggd
Kggd
Kggd
Kggb
Kggb
Kggb
Kggb
KJmv
KJmv
KJmv
KJmv
Tof
Tof
Tof
TofTof
Tof
Tof
Tof
Tmv
TmvQya Tp
KJmv
Kggd
To
Qoa
Qoa
To
Tof
Qoa
KJmv
KJmv
Kggd
Kgt
Kgt
KJmv
KJmv
KJmv
Qoa
Qya
Qw
KJmv
Tof
TofQoa
Qoa
Qya
To
To
To
Qls
Qls?
Qls?
Qls?
Qls?
Qls?
Qls?Qls?
Qya
Qya
Tsd
Qls?
Qls?
Qls?
Qls?
KJmv
QlsQls
Qls?
Qoa
Qoa QyaTmv
Qoa
Qvoa
Qoa
Tmv
Qya
Qya
Qya
Qw
Qya
KJmv
DEPARTMENT OF
CONSERVATION
California
Geological Survey
GN
240 MILS13
0 021 MIL
MN
UTM GRID AND 1988 MAGNETIC NORTHDECLINATION AT CENTER OF SHEET
1/2
0
0
0
1
1
1.5
.5 2
2
2Thousand Feet
Kilometers
Miles
Scale 1:24,000
REFERENCES
Kennedy, M.P., and Peterson, G.L.,1975, Geology of the San Diego metropolitan area,
California; Section B, eastern San Diego metropolitan area: California Division of
Mines and Geology Bulletin 200, p. 43-56, scale 1:24,000.
Kennedy, M.P., and Tan, S.S., 1977, Geology of National City, Imperial Beach, and Otay
Mesa Quadrangles, southern San Diego metropolitan area, California: California
Division of Mines and Geology, Map Sheet 29, scale 1:24,000.
Kuper, H.T., and Gastil, R.G., 1977, Reconaissance of marine sedimentary rocks of south-
western San Diego County, California, and northwestern Baja California: San Diego
Association of Geologists, p. 9-15. Plate 2, scale 1:24,000.
Tan, S.S., 1992, Landslide hazards in the Jamul Mountains quadrangle, San Diego County,
California: California Division of Mines and Geology Open-File Report 92-12,
Geologic Map - Plate 29B, scale 1:24,000.
Mexico
Alpine
El Cajon
Jamul
United States
Ramona
67
94
1
2
4
Mexico
Alpine
El Cajon
Jamul
United States
Ramona
67
94
1
2
4
Santee
San
Ysidro
Chula
Vista
National
City
La MesaSan
Diego
Escondido
PowayDel Mar
Oceanside
15
S4
805
5
785
78
8
0 5 10
Miles
P A
C I F
I CO
C E
A N
INDEX MAP
1. San Vincente Reservoir quadrangle
2. El Cajon quadrangle
3. Jamul Mountains quadrangle
4. Otay Mesa quadrangle
Santee
San
Ysidro
Chula
Vista
National
City
La MesaSan
Diego
Escondido
PowayDel Mar
Oceanside
15
S4
805
5
785
78
8
0 5 10
Miles
P A
C I F
I CO
C E
A N
INDEX MAP
1. San Vincente Reservoir quadrangle
2. El Cajon quadrangle
3. Jamul Mountains quadrangle
4. Otay Mesa quadrangle
THIS
MAP
33
Quartz
Syenite
Quartz
Monzonite
Quartz
Monzodiorite
Syenite Monzonite Monzodiorite
Granite
Alk
ali-
feld
spar G
ranite
Tonalite
Diorite
Sye
nogra
nite
Gra
nodio
rite
Monzo
gra
nite
Quartz
Dio
rite
90 65 35 10
5
20
60Q 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.
MAP SYMBOLS
Contact between map units.
Air photo lineaments that define major joints. No significant evidence of
faulting has been observed along these features.
Strike and dip of inclined sedimentary beds.
Strike and dip of inclined foliation in metavolcanic rocks.
Strike and dip of inclined foliation in igneous rocks.
Landslide (Qls) - arrow(s) indicate principal direction of movement, outline
includes headscarp of landslide. Querried where questionable.
5
?
50
25
Qw
Qya
Qoa
Qls
Tp
Tmv
Kgt
Kggd
Kggb
KJmv
Qvoa
Tsd
To
Tof
Late Holocene active channel and wash deposits; unconsolidated sand, silt,
gravel and clay. Deposits along smaller drainage channels are included in Qya.
Holocene alluvial deposits unconsolidated to locally poorly consolidated silt, clay,
sand and gravel. Included modern active sedmients along small drainage
channels.
Landslide deposits (Holocene and Late Pleistocene). Landslide slump and rock
fall deposits. On map, the deposit is depicted by landslide arrows (see "MAP
SYMBOLS"). Querried where questionable.
Late Pleistocene alluvial deposits; moderately consolidated, poorly sorted flood
plain deposits consisting of gravelly sandy silt and clay.
Middle Pleistocene alluvial deposits; well consolidated, poorly sorted flood plain
deposits consisting of gravelly, sandy silt and clay.
San Diego Formation (Pliocene); poorly indurated, fine- to medium-grained
sandstone, typically yellowish to light brown.
Otay Formation (Oligocene to Miocene); poorly indurated massive light-colored
sandstone, siltstone and claystone, interbedded with bentonite lenses.
Otay Formation - fanglomerate facies (Oligocene to Miocene); poorly cemented
bouldery conglomerate and coarse-grained sandstone. Interfingered with
overlying To.
Pomerado Conglomerate (middle Eocene); poorly to moderately cemented
massive cobble conglomerate with sandstone interbeds.
Mission Valley Formation (middle Eocene); poorly to moderately indurated light-
colored marine medium-to fine-grained sandstone with cobble conglomerate
lenses. Interfingers with underlying Stadium Conglomerate.
Tonalite (Cretaceous); includes some granodiorite and quartz diorite; medium-
grained; generally dark colored and severely weathered.
Granodiorite (Cretaceous); includes some tonalite and monzogranite; medium-to
coarse-grained.
Gabbro (Cretaceous); includes some peridotite, norite, quartz gabbro; medium-
grained and dark colored.
Metavolcanic rocks (Jurassic and Cretaceous); mildly metamorphosed volcanic,
volcaniclastic and sedimentary rocks. Volcanic rocks range from basalt to rhyolite,
but are predominantly andesite and dacite.
DESCRIPTION OF MAP UNITS
CENOZOIC
MESOZOIC
CORRELATION OF MAP UNITS
Qoa
Qw
Pleistocene
Holocene
QUATERNARY
CRETACEOUS
JURASSIC
TERTIARY
Qya
Eocene
Qls
Kgt Kggd Kggb
Tp
Tmv
Qvoa
PlioceneTsd
To
Tof
Oligocene/
Miocene
KJmv
GEOLOGIC MAP OF THE
JAMUL MOUNTAINS 7.5' QUADRANGLE
SAN DIEGO COUNTY, CALIFORNIA:
A DIGITAL DATABASEGeologic Mapping by
Siang S. Tan
Digital Preparation bySybil Jorgensen and Jonathan Williams
2002
This map was funded in part by the USGS
National Cooperative Geologic Mapping Program,
STATEMAP Award no. 01HQAG0092.
32o 37' 30"
117o 00'
32o 45'
117o 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
Topographic base by U.S. Geologic Survey
7.5' Jamul Mountains Quadrangle
Polyconic projection, contour interval 20 feet,
dotted lines 10 feet.
32o 37' 30"
116o 52' 30"
32o 45'116
o 52' 30"
CALIFORNIA GEOLOGICAL SURVEY
JAMES F. DAVIS, STATE GEOLOGIST