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Geologic Considerations
inConservation
PlanningSouthern California
December 3-5, 2002JGrim
Discussion Topics
1. California Geology 101
2. Southern California Geology
(Lunch)
3. Geologic Considerations in Conservation Planning
4. Geologic Hazards
5. Pertinent NRCS Policies & Procedures
6. Available Resources
California Geology 101
Geologic Time Scale
Rocks
Structure
Plate Tectonics
Process through Time
THE ROCK CYCLE
Rock Types
Igneous
Sedimentary
Metamorphic
Igneous Rocks
Intrusive Igneous
e.g Granite
Granite
Granite Mountains,San Bernardino Co.
Igneous Rocks
Extrusive/Volcanic
(e.g. Basalt)
Pillow Basalt
Conejo Volcanics on Kanan Rd, Santa
Monica Mtns.
Cindercones
Red Hill, just north of Little Lake near
395, Inyo Co.
Volcaniclastic Rocks
Ricardo Group, Red Rock Canyon, Kern
Co.
Sedimentary Rocks
Sandstone
Sandstone & Shale
Sespe Formation near Casitas Pass, Ventura Co.
Sedimentary Rocks
Conglomerate
Eocene Llagas Fm, Rambla Pacifico, Santa Monica Mtns.
Sedimentary Rocks
Breccia
Blackhawk Slide Breccia derived from Furnace Marble
(Rd. 247, San Bernardino Co.)
Metamorphic Rocks
Slate (top) vs. Shale
Metamorphic Rocks
Schist
Metamorphic Rocks
Gneiss (and Skittles)
Serpentenite
North Baker Beach, Presidio
Geologic Structure
Folds
Joints & Fractures
Faults
Geologic Structure results when rocks and sediments are
subjected to:
Tension
Compression
Shear
Uplift
Folds
Ventura Anticline
San Miguelito Anticline in Pico Formation beds
near Ventura
Oil Accumulations in Anticlinal Crests
Natural Oil SeepsOjai Road
Barstow Syncline
Folded Miocene shales and sandstones in
Rainbow Basin (north of Barstow)
Santa Ana Canyon east of Yorba Linda
Joints & Fractures
Joints & Fractures
Campo Reservation, San Diego Co.
Folding & Faulting
Anaverde Formation in San Andreas Fault Zone, Highway 14
near Palmdale
Brittle vs. Ductile Failure
Blind Thrust Faults
Northridge Earthquake, Jan.
1994
Reverse & Thrust Faults
Hollywood and Vine
Normal Faults
1872 Owens Valley Earthquake
Strike-Slip Faults
Left-Lateral
Right-Lateral
Highway 247
1952 Kern Co. Quake
1992 Lander Earthquake
Hwy 58 west of Hwy 223
California Geology
Telling the story with Plate Tectonics
California Geology
Plate Boundaries
Convergent Boundaries-
magmatic intrusions and volcanism
Convergent Boundaries-
Magmatic intrusions and volcanism
Convergent Boundaries-
Magmatic intrusions and volcanism
California Geology
California GeologyPRECAMBRIAN (>570 my
bp)
California GeologyPRE-CENOZOIC (<570 my
bp)
Metamorphics
California GeologyPALEOZOIC (570-245 my
bp)
Antler Orogeny(approx. 350 my bp)
California GeologyPALEOZOIC (570-245 my
bp)
SedimentaryVolcanics
Metamorphics
California GeologyEARLY MESOZOIC (245-150 my
bp)
Sierran Trench
California GeologyEARLY MESOZOIC (245-150 my
bp)
SedimentaryVolcanics
Metamorphics
California GeologyMESOZOIC (245-65 my bp)
SedimentaryVolcanics
Metamorphics
Granitics
California GeologyMID-LATE MESOZOIC (140 my bp)
Franciscan Trench
California GeologyLATE MESOZOIC (140-65 my bp)
Great Valley Sed.
California GeologyLATE MESOZOIC (140-65 my bp)
Great Valley Sed.Ultramafics
(Serpentenite)
California GeologyLATE MESOZOIC (140-65 my bp)
Great Valley Sed.Ultramafics
(Serpentenite)
Franciscan
The San Andreas “Zipper”
23my
14.5my
7.5my
3my
California GeologyMID-LATE TERTIARY (30-2 my bp)
California GeologyCENOZOIC [(40) 17-my bp-Pres.]
Volcanics
California GeologyCENOZOIC (24-2 my bp)
Marine Sedimentary
Sierra Nevada Uplift (3-5 my bp)
California GeologyLATE CENOZOIC - RECENT
Nonmarine Sedimentary
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
The San Andreas “Zipper”
Geology of Southern California
Complexity is thy
middle name
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