BIOL 1080 Lecture Notes - Lecture 3: Continental Crust, Oceanic Crust, Continental Drift
Document Summary
Geography of the ocean basins: the world ocean is the dominant feature on the earth in terms of total area, 61% of the total area of the northern hemisphere is ocean, as is about 80% of the southern. Hemisphere: the world ocean is divided into four large basins: pacific, atlantic, indian, and artic. Structure of the earth: the earth is thought to have originated 4. 5 billion years ago, from dust accumulated from the big. Lighter components formed a thin crust for sustaining life. Internal structure of the earth: core- innermost layer; solid inner core and liquid outer core; iron-rich, mantle- middle layer; semi-plastic composition, crust- outermost layer; thinnest portion of the earth. Continental drift: proposed in 1912 by alfred wegener, he suggested that all continents had be joined in a single supercontinent, which he named. Pangaea (whole earth: he proposed that pangaea began up to 18 million years ago, not widely accepted at the time.
