Tilting Erosion University of California, Berkeley Professor Ken Johnson Civil Engineering 70 Engineering Geology Civil Engineering 70 Lecture 9 9/25/07 Evolution of Geologic Time Scale • Time Measures o Relative Age Based on stratigraphic principles Uses fossils assemblages to establish Formations o Numerical Age Measurment with the usage of atomic physics • Stratigraphic Basics o Principle of original horizontality – sediments deposited in essentially horizontal beds o Principle of Superposition – sediments that lie above other sediments are younger than the sediments they overlie o Uniformitarianism • Unconformities o Mark missing time periods o Indicate uplifting tectonic forces that cause erosion or global se level changes o Disconformity – erosional surface between horizontal beds o Nonconformity – erosional surface between sediments and underlying igneous or metamorphic rocks o Angular Unconformity – erosional surface where beds are not parallel
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This note was uploaded on 04/02/2008 for the course CE 70 taught by Professor Johnson during the Fall '07 term at Berkeley.