GEOG 111 Lecture 9: GEOG 111 (Physical Geography, Kernan) Lectures Seventeen and Eighteen
Document Summary
Geog 111 - lectures seventeen and eighteen - 10/17 + 10/19. Uniformitarianism: the present is the key to the past" what we observe today we can look back on and understand the past. Geologic time scale: all of earth"s history of 4. 6 billion years, hierarchical in nature, starts with long eons within which are eras, then period, then epochs. Earth"s structure: inner core made up of solid materials due to mass of earth"s materials around it and is extremely hot, outer core is liquid, lower mantle, upper mantle, asthenosphere, crust. Lithosphere made up of the asthenosphere, uppermost mantle, and the crust. The rotating of the earth causing the outer core to slosh around is what generates earth"s magnetic current. Tectonic cycle: causes earth"s plates to move to new locations. Rock cycle: how earth materials transition to different types. Only a handful of elements make up earth"s crust. Three classes of rocks that make up earth"s rock cycle.
