| A | B |
|---|
| mantle thickness | 29000 km, 16000 mi |
| core thickness | 3400 km, 2000 mi |
| crust thickness | 5 to 50 km 3-30 mi |
| outer core | liquid Fe and Ni |
| inner core | solid Fe and Ni, hottest place on Earth (10000-18000 F), the pressure from the heat is so immense that the Fe and Ni cannot move freely |
| lithosphere | composed of the crust and the upper most part of the mantle, 60 - 100 km thick, cool solid brittle rock |
| asthenosphere | in upper part of the mantle, 200 (100 m) km thick, hot semi liquid rock |
| oceanic crust | in ocean, made out of less dense rock, thicker (10-30m) |
| continental crust | on land, less dense rock, is thinner (3-10 mi) |
| density | how compact the atoms are (mass per volume) |
| Alfred Wegener | german metorologist (weather) who proposed the cdt |
| 1.1 bya | Rodinia, single cell bacteria and algae |
| 850 mya | Rodinia into fragments |
| 700 mya | Gonwanaland and Laurasia |
| 550 mya | gon. and Laur. moving towards each other |
| 300 mya | Pangea |
| 200 mya | Pan. into Gonwanaland and Laurasia, dinosaurs |
| 135 mya | Gon. into Afica, Australia, South America, Antarctica and India |
| 40 mya | Laur. into North America, Europre/Asia and Greenland |
| 35 mya | india into Asia |
| evidence for cdt (6) | looks like continents fit together, glaciers on tropical islands,tropical fossils on Antarctica, similar landscapes on different continents, rocks of the same age and type on continents, same fossils on different continents |
| 2 reasons why sientists did not believe cdt | changed the ideas of the Earth, metorolist proposing a theory in geology |
| main weakness of cdt | did not explain how con. move |
| mid ocean ridge | a long underwater moutain ridge with a deep valley in between, made by convection cells, new crust is made from magma |
| theory of PTT | the Earth's litho is divided into plates, plates float on the asten and are constantly movong b/c of convection cells |
| plate | big chunk of litho |
| 2 differences in Ptt and cdt | cdt- only land moves, ptt- land and oceanic, cdt- could not explain how continents moved |
