GEO 1111 Lecture Notes - Lecture 3: Partial Melting, Convergent Boundary, Thermal Subsidence

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Donald Cummings

Document Summary

2 peaks : 840m above sea level (continents), 2. 3 km below sea level (oceans) Oceanic crust : basaltic (mg & fe rich = mafic) Continental crust : granitic (si (feld spars) and quartz rich = felsic) 260 mya of erosion, therefore sediment is thin. Explanation for similar rocks, plants, animals on dif continents. Narrow strip of low-density, felsic rock that crossed oceans. Had risen and sunk over time, allowing animals to pass. Earth is layered ( 2 layers, liquid outer core & viscoelastic mantle), convection driven by heat flow from decaying radioactive elements outward towards earth"s cold surface. Stated that continents could not have plowed through the basaltic oceanic layer. Continental drift was not accepted due to lack of data. Deep ocean extremely hard to map b/c water is opaque and high pressure. Even today only 5% of deep oceans has been discovered. Measures depth, measures time to hit and come back. Used as metal detectors to locate enemy submarines.