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Welcome to ES150: Structural Geology. January 4, 2005. First Day Stuff. Course Objectives Go over Syllabus Lab Schedule Course Calendar Waiver What is Structure About? Any questions about tsunamis? And on to… Quick overview of the state of California. What is Structural Geology?.
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Welcome to ES150:Structural Geology January 4, 2005
First Day Stuff • Course Objectives • Go over Syllabus • Lab Schedule • Course Calendar • Waiver • What is Structure About? • Any questions about tsunamis? • And on to… Quick overview of the state of California
What is Structural Geology? • Study of Forces and Stress that affect and modify the solid earth • Rock deformation resulting from that stress (= strain) • Plate scale tectonics (geologic history) • Regional scale activity (terranes) • Outcrop scale • Microscale (minerals and fine rock fabrics)
What Structure Does • Stresses are due to tectonic plate motions • Structures in Rocks preserve information about past stresses • Structural geologists correlate back across time and different scales to reconstruct paleo-tectonics
Economic Reasons to do this • Metallic Ore Deposits often reside in ancient continents collision zones and in fault breccias • Hydrocarbon resources travel along faults and collect in the tops of folds • Faults create hazards • Rock failure studies are important to infrastructure • Geothermal heat in extensional faults can be used to produce energy (with help from Ty).
Academic Reasons to Do this • Understand Earth History - How have the continents moved in the past? • Understand Earth Processes - How do mountain ranges form? • Exciting field work opportunities!
Measured Rotation 2mm Microscale
Measured Local Pressure Outcrop Scale
Local Stresses Over Large Area Regional Scale
Alleghanian Orogeny builds Appalachians When North America hits Gondwanaland Plate - Scale
Giant Quake and Tsunami12/26/04 http://www.ineter.gob.ni/geofisica/tsunami/com/20041226-indonesia/rupture.htm
OnToCalifornia…A quick overview of what structural studies have revealed…
TECTONIC REGIONS OF CALIFORNIA KLAMATH MTS MODOC PLATEAU SIERRA NEVADA MICROPLATE GREAT VALLEY COAST RANGES MOHAVE DESERT BASIN & RANGE TRANSVERSE RANGES
ACTIVE FAULTING IN CALIFORNIA JUAN DE FUCA TRENCH SIERRA FRONT / BASIN & RANGE SAN ANDREAS FAULT GARLOCK FAULT
Pre-Cambrian California Warm, tropical, carbonate reefLike this photo only no people and no coral yet
Paleozoic California Micro-continent 50-car pile-up Imagine terranes accreting west-to-east in CA
MESOZOIC (235-65Ma) IGNEOUS ROCKS OF CALIFORNIA MESOZOIC (235-65Ma) DEEP MARINE SEDIMENT MESOZOIC (235-65Ma) SHALLOW MARINE
Pre-Sierras Central Valley Coast Ranges MESOZOIC CALIFORNIA
CENOZOIC (65Ma-NOW) IGNEOUS ROCKS OF CALIFORNIA CENOZOIC SEDIMENT
CENOZOIC SED. CENOZOIC IG. MESOZOIC SED. MESOZOIC IG. PALEOZOICPre-CAMBRIAN
JUAN DE FUCA TRENCH SIERRA FRONT / BASIN & RANGE SAN ANDREAS FAULT GARLOCK FAULT