welcome to es150: structural geology january 4, 2005

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!

Microscale

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

2mm

Measured Rotation

Outcrop Scale

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Measured Local Pressure

Regional Scale

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Local Stresses Over Large Area

Plate - Scale

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Alleghanian Orogeny builds AppalachiansWhen North America hits Gondwanaland

Giant Quake and Tsunami12/26/04

http://www.ineter.gob.ni/geofisica/tsunami/com/20041226-indonesia/rupture.htm

Quake Location - First Rupture

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Moment (=energy) distribution

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

OnTo

California…

A quick overview of

what structural studies have

revealed…

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

MODOC PLATEAU

KLAMATHMTS

SIERRA NEVADAMICROPLATE

MOHAVEDESERT

GREAT VALLEY

COASTRANGES

BASIN &RANGE

TRANSVERSERANGES

TECTONIC REGIONS OF CALIFORNIA

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

SA

N A

ND

RE

AS

FAU

LT

GARLOCKFAULT

ACTIVE FAULTING IN CALIFORNIA

SIERRA FRONT / BASIN & RANGE

JUAN DEFUCA TRENCH

Pre-CAMBRIAN (4.5Ba-570Ma)

ROCKS OF CALIFORNIA

Pre-Cambrian California

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Warm, tropical, carbonate reefLike this photo only no people and no coral yet

PALEOZOIC (570-235Ma) ROCKS OF

CALIFORNIA

Paleozoic California

Micro-continent 50-car pile-up Imagine terranes accreting west-to-east in CA

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

MESOZOIC (235-65Ma) IGNEOUS

ROCKS OF CALIFORNIA

MESOZOIC (235-65Ma) DEEP

MARINE SEDIMENT

MESOZOIC (235-65Ma) SHALLOW

MARINE

QuickTime™ and aVideo decompressor

are needed to see this picture.

MESOZOIC CALIFORNIAPre-Sierras

Central Valley

Coast Ranges

CENOZOIC (65Ma-NOW) IGNEOUS

ROCKS OF CALIFORNIA

CENOZOIC SEDIMENT

CENOZOIC SED. CENOZOIC IG.

MESOZOIC SED. MESOZOIC IG. PALEOZOIC

Pre-CAMBRIAN

SA

N A

ND

RE

AS

FAU

LT

GARLOCKFAULT

SIERRA FRONT / BASIN & RANGE

JUAN DEFUCA TRENCH

QuickTime™ and aAnimation decompressor

are needed to see this picture.

80 Million Yrs to Today

QuickTime™ and aVideo decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.