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California Geology
I. California Resources
A. Agriculture
Citrus fruits,
dates,
Vegetables
Grapes
Volcanic soil erosion, is
a main reason for fertile
soil in California
Mild climate in the
central valley and
coastal mountains
also helps crops
grow.
B. Minerals
This is the massive gold-bearing quartz vein known
as the "Mother Lode".
Highway 108 at Woods Creek, west of
Jamestown, CA
1.Past volcanoes laid the
quartz rock for CA gold
in the Jurassic batholith
formation. Earthquakes
and erosion revealed
the ore
California's first gold rush was here,
just north of San Fernando, in
Mexican days.
In addition to gold and
mercury,
2. CA minerals include
copper, silver and iron.
These pictures are a mercury mine and
copper ore.
3. Salts are also
produced in CA
Borax mined in Death Valley was
originally transported to market in heavy
wagons drawn by 20 mules.
Harmony Borax Mill, Death Valley NM, CA
Charcoal made in these kilns near Death Valley
was used to smelt lead ore in the mines at
Darwin.
near Wildrose, Death Valley NM, CA (1969).
Granite used in many of California's best
known public buildings was quarried in
the Sierra foothills near Raymond.
Raymond, Madera County, CA
C. Water
CA’s natural water is
from run-off and
ground water. 2/3
of CA water comes
from the
Sacramento River,
the San Juaquin
River and the
tributaries from the
San Francisco Bay
Coastal Areas get their
water from
groundwater. The
runoff from the
Coastal Range
provides 90% of this
water.
Southern California
depends on the CA State
water project moving
water from the San
Francisco Bay area to
areas of increasing
population
Southern California also
gets water from the
Colorado River. The
Colorado River Compact
of 1922 provides for 4.4
million acre feet of
water to be piped to CA
to recharge their
underground water
storage.
Palm Springs' lush golf
courses are made
possible by its
abundant groundwater
resources.
Palm Springs, CA
Central California also
gets water from the
SF bay area through
the Central Valley
water project to
support it’s
agricultural industry.
This imported water
joins the Sierra
Nevada runoff water
in an underground
aquifer
This dam blocks the Tuolumne River
and floods Hetch-Hetchy Valley.
O'Shaugnessy Dam, Tuolumne
River, Yosemite NP, CA
Hetch-Hetchy Reservoir stores
water for the San Francisco
system.
Hetch-Hetchy Reservoir, Yosemite
NP, CA
Even though 60% of
CA water used by
people in CA comes
from the northern
part of the state, it is
the southern
population that uses
over half of the
water.
Most of CA’s
residential water is
for landscaping and
not drinking or
household use.
D. Oil/Natural Gas
One of the more
prolific oil and
natural gas
producing regions
in the world: Los
Angeles Basin,
Bakersfield, and
Santa BarbaraVentura Channel
The Westside oil fields in the southern San
Joaquin Valley once bristled with wooden oil
derricks and pumps like these.
Buena Vista Hills, north of Taft, CA
In addition
hydroelectric power,
wind energy,
nuclear energy and
geothermal energy
are all generated in
California
Shifting plates have
helped create CA’s
oil, natural gas
reserves and
geothermal
reserves.
II. Geology
A.
California Geological Regions
B.
Timeline of Region
Formation
Pre Jurassic
Jurassic
155 MYA
Basement Rocks laid down in ancient seas
Nevada was edge of land until a volcanic island arc
much like Japan today collided with our western coast.
These Cascadia mountains which were located where
the present north west corner of CA is located, began to
erode and fill in the ocean to form CA
Ancestral Sierra mountains formed by large batholiths of
granite. Ocean sediments were deposited and thrust up
against mountains
Cretaceous
CA under shallow sea except Sierra Mountains.
130 MYA
Paleocene
Eocene
75 MYA
Lava erupts in Klamath Mt Ranges due to subduction
CA land moist and swampy
Oligocene
Epoch
Seas shrink and CA not underwater. CA mostly hills and
plains
38 MYA
Early Sierras are eroded away and sediment fills Great
Valley
Miocene
Epoch
28 MYA
Mountains rise on West side and cut off moisture
Sierra Nevada tilt and thrust up
Fissure eruptions of lava occur in Modoc Plateau
Volcanoes in Central CA because of Pacific plate
subduction
Great Central Valley under sea
Pliocnece
Mountains in both Coast Range and Sierras are elevated
Epoch
Sierras are tilted up on eastern side and slope down into
the central valley
9 MYA
Volcanic action in the northern Sierra and Northern CA
covers much of the land with lava and mud flows
Pleistocene
Glaciers cover the higher eastern mountains four times
Epoch
Lakes are formed in eastern CA
1 MYA
Active faulting/folding and mountain building, especially
in the Basin and Range
Recent
Epoch
Coastal Ranges are still lifting
22,000 years
ago/today
San Francisco Bay is formed
Large lakes in the east dry up and leave large salt beds
Continued volcanic eruptions in the NE
III. Issues Today
A. San Andreas Fault a
large strike/slip fault is
a plate division,
predicted to break at
any time.
B. Pacific Plate is moving
northwest interacts
with the North
American Continental
Plate.
B. Erosion –
1. Gravity and
movement of soil
particles from water
and wind Can cause
landslides
Example:
San Francisco Delta
Area, Landau Sand
Area.
C. Landslides are
caused by erosion,
earthquakes and
heavy rainfall.
Examples are house falling off the
hills above beaches in SCA.
D. Pollution