Update 2026 | Exam Prep | Graded A+
Anorthosite - correct answerA plutonic igneous rock composed almost entirely of
plagioclase feldspar, found in the San Gabriel Mountains and dated at 1.022 billion
years.
Connate Water - correct answerWater trapped in a formation at the time of deposition
Franciscan Formation or Group - correct answerA heterogeneous unit of sedimentary
and volcanic rocks consisting of greywacke and interbedded shale, minor amounts of
chert, limestone, greenstone, and metamorphic rocks of greenschist and blueschist
facies. The formation may be 50,000 feet thick. It is one of the basement types in the
Coast Ranges.
Great Valley Sequence - correct answerShallow self to submarine fan deposits of
sandstone, shale, siltstone, and minor conglomerate and limestone of Late Jurassic to
Late Cretaceous age. These deposits, attaining a maximum thickness of approximately
80,000 ft, were thrust over the Coast Range ophiolite above the Franciscan formation.
Lake Corcoran - correct answerA freshwater lake that covered much of the western San
Joaquin Valley about 600,000 years ago (Late Pleistocene). Freshwater deposits lake
clays, volcanic ash, and diatomite of Corcoran Clay member of Tulare formation.
Los Angeles Basin - correct answerA large downwarped basin formed in Late Tertiary
that received thousands of feet of marine sediments. The basin produces petroleum in
prolific quantities. Located in the Peninsular Ranges in southwest tip of CA
Ophiolite - correct answeran igneous rock consisting largely of serpentine, believed to
have been formed from the submarine eruption of oceanic crustal and upper mantle
material.
Monterey Formation - correct answerA widespread Miocene marine formation
consisting of siliceous shales and cherts. Silica was deposisted as diatomites and silicic
ash beds. Phosphates were also deposited in the formation. The Monterey Formation is
the most likely source of much of the petroleum and natural as in the Transverse
Ranges Province.
Overdraft - correct answerThe condition of water withdrawal by pumping exceeding the
amount of water recharged, occurring over a time frame longer than a year.
Pelona Schist - correct answerLow-grade metamorphic rock of Cretaceous age in
Transverse Ranges.
,Salinian Block - correct answerThe structural block located west of the San Andreas
fault zone and east of the Nacimiento fault zone. The basement is composed of Late
Cretaceous granitic rocks similar in composition to the Sierra Nevada granitic rocks.
The granitics are the other main basement type in the Coast Range Province (located
along the western coast)
San Andreas Fault - correct answerThe most important fault in CA - a northwest-
trending, right-lateral strike slip fault, 750 miles long, extending from Shelter Cove in the
north to the east side of the Salton Trough. The fault forms the plate boundary between
the Pacific and North American Plates and separates Franciscan formation from the
Salinian Block in the Coast Ranges Province.
Sierra Nevada Batholith - correct answerA great uplifted block of granitic rocks intruded
and uplifted beginning in the Late Jurassic. The bulk of the rock was emplaced during
the Cretaceous. Granitic compositions range from granite to quartz monzonite, quartz
diorite, and granodiorite.
Santa Ynez Fault - correct answerBoundary fault between the Coast Ranges and
Transverse Ranges Province and separating Franciscan basement of Late Jurassic age
from Transverse Ranges basement.
Southern California Batholith - correct answerThe dominant rock outcrop of the
Peninsular Ranges, consisting of gabbro, diorite, quartz diorite, quartz monzonite, and
granite. Quartz diorite predominates. Batholith was emplaced mainly during the
Cretaceous.
Subjacent Series - correct answerOne of two major subdivisions of rocks in the Sierra
Nevada and Klamath Mountains Province applied to the rocks younger than the
Nevadan orogeny that emplaced the Sierra Nevada batholith.
Sutter Buttes - correct answerA prominent circular feature in the Central Valley that is
volcanic in origin. The core is andesite and tuff and is surrounded by rhyolite porphyry.
Explosive activity was recorded in the Pleistocene. This feature has produced traps for
natural gas.
Klamath Mountains Province - correct answerProvince found between the northernmost
Coast Ranges and Cascade Ranges and the Great Valley to the south. The western
boundary is defined by the South Fork Mountain thrust fault. Several irregularly oriented
mountain ranges are found in the Klamath Mountains, including: Trinity Alps, Salmon
Mountains, Scott Bar Mountains, Siskiyou Mountains, and Marble Mountains.
Topography: moderate peaks (6000-9000 ft EL). Abundant rainfall, Salmon, Shasta,
Sacramento, Scott, Klamath, and Trinity Rivers drain the area.
Key Formations:
1.alluvium/glacial deposits-gravel, sand, mud, Au bearing;
2.Pleistocene Red Bluff
, 3.Plio-Pleistocene Tehama-stream grvl, s, volcanics & lake sediments
4.Miocene Wimer-yngst marine unit, ss, sh, cgl, 150ft; cgl forms ridge tops; contains Ni
minerals
5. Oligocene Weaverville-folded & faulted ss, sh, tuff, & lignite deposited on swampy
floodplains; 2000 ft thick; similar to Ione, contains Au, phosphates
6a. Cretaceous Hornbrook (Great Valley seq, Upper)-Oldest superjacent series rocks,
2000ft thick, lie unconformably on granite & older fms. Shallow-water marine &
fossiliferous, well-bedded mudstone, sh, & cgl; basal cgl Au-bearing. Great Valley -
marine cgl at base, pebbles of mica schist; E K pelecypods & ammonites.
6b. South Fork Mountain schist-youngest subjacent series rocks; well-foliated quartz-
mica schist, with glaucophane-crossite; closely related to Franciscan fm; Klamath Mtns
were thrust over and attached to Coast Ranges along South Fork Mountain thrust.
.7..... AHHH TOOO MANY!!!
Active Fault - correct answerA fault that has exhibited surface displacement within
Holocene time (about 11,000 years) as determined by the California Geological Survey
under the Alquist-Priolo Earthquake Fault Zoning Act. Other state and federal agencies
define activity differently based on the faulting type and tectonic regime.
Afterslip - correct answerA seismic fault slip that occurs following a large earthquake.
Asthenosphere - correct answerUnder the lithosphere, it is weak upper mantle where
isostatic adjustments are made, magma generated and seismic waves strongly
attenuated.
Attenuation - correct answerA reduction in the amplification of seismic waves produced
by divergence, scattering, reflection, and absorption
Avalanche - correct answerA large mass of snow, ice, soil, rock or mixtures of these
materials, falling, sliding, or flowing very rapidly due to gravity.
Body Wave Magnitude - correct answerMagnitude of an earthquake as estimated from
amplitude of body waves.
Creep - correct answerAseismic fault slip
Crown - correct answerThe material that is still in place and adjacent to the highest
parts of the main scarp of a landslide.
Differential Settlement - correct answerThe uneven lowering of different parts of an
engineered structure, often resulting in damage to the structure.
Dilatancy - correct answerThe increase in volume of rocks due to elastic and nonelastic
changes during deformation