CEE 437 Lecture 1

October 1, 2002

Thomas Doe

Outline

• Course Introduction

• Geology and Engineers

• Brief History of Geology

• Global Structure

• Plate Tectonics

• The Rock Cycle

TopicCourse Introduction, Earth Structure and CompositionMinerals, Rock Cycle, LabSedimentary Rocks, Stratigraphy, Geologic TimeIgneous and Metamorphic Rocks, LabGeologic Maps and StereonetsStructural GeologyField Trip #1, Seattle GeologyPhysical Properties of Rocks and SoilsRock Mass Classification IndicesFracture Characterisation and Fractured Rock Analysis

Rocks Slope and TunnelsMid TermField Trip #2, CascadiaSite Characterization, Borehole Characterization and GeophysicsLandslides and SubsidenceEarthquakes and SeismologyEngineering Geology in Washington StateGlacial GeologyThanksgivingField Trip #3: Glacial GeologyHydrogeology I — PrinciplesHydrogeology II — Site CharacterizationFinal Exam

Geology — Brief History

• Origins in late 18th and early 19th Centuries

• Catastrophism and Uniformitarianism– Age of Earth– Uniformity of Processes

• Plate Tectonics Revolution (1950’s to 1980’s)

• Neo-Catastrophism

Siccar Point Unconformity

Smith’s Map of England

Engineering and Geology

• William Smith and the English geological map

• Karl Terzaghi and insights to the distribution of earth materials

• Earth heterogeneity!!!!

Global Structure

• Based mainly on seismic information and meteorite compositions

• Crust ~25-75 km depending varyin under continents and oceans

Global Structure

Velocity Variation with Depth

Development of Plate Tectonics

• Evidence from ocean floor magnetism and ages

• Evidence from seismicity

• Evidence from cross-continent correlations of rocks

Global Seismicity

Benioff Zone

Sea-floor Spreading

• Mantle convection driven

Seafloor Spreading — Sediment Ages

Evolution of Spreading Sea Floor — Atlantic Analog

Convergent Margins

• Ocean to Continent

• Continent to Continent

Convergent Margin

Rock Cycle

Convergent Margin — Subduction Zone

Major Crustal Plates

Evolution of Continents — North American Craton

North American Accretion