GEOLOGY 103 Lecture Notes - Lecture 4: Magic 2Ch, Radiometric Dating, Oceanic Basin

• School: UMASS-Amherst
• Department: Geology
• Course: GEOLOGY 103
• Professor: Stephen Burns

Document Summary

Structure of the earth and origins of ocean basins: Age of continents is old (>3500 million years) while the age of ocean floor relatively young (<200 million years) Earthquake: releases a tremendous amount of energy (seismic energy . Seismic waves radiate away from the point of origin (=focus) 3 different types of waves: rayleigh waves: travel along surface of earth, p-wave: travel fast through the earth. Compression-relaxation motion like wave: s-waves: are slower and cannot travel through liquids. Radiometric dating: of meteorites found on earth, rocks brought back from the moon (~4. 6 billion yrs. ) Early earth very hot, high heat flow, rapid degassing (volcanism), intense meteorite bombardment. Early atmosphere rich in co2, ch4, h20, hcl, h2s, n2, (no free oxygen) The age of earth (4. 6 ga) has been determined by radiometric age dating meteorites. Meteorites are fragments of larger parent bodies that formed early in history of solar system.