1. List the layers of the earth from the least dense to the most dense.
Warm Up 9/7/2010 (copy the question and answeron p12 of notebook, save room for more writing)
1. The glass shows the results of a density lab. Which layers of the earth could be represented by each layer?
List the layers of the earth from the least dense to the most dense.
H/W: vocab set 1, day 4 create practice quiz
study for vocab 1 qiuz , read section
oil
Earth’s layer
water
Earth’s layer
Corn syrup
Earth’s layer

2. EQ: How do the characteristics and composition of the layers of the earth contribute to evolution of earth’s surface? Obj: TLW be able to describe the evidence supporting the theory of continental drift by completing a foldable using information obtained from the textbook and video and answering EQ in I.N.

3. Continental Drift Foldable
Fold two sheets of paper and label as follows
Bottom sheet
Continental Drift
Top sheet
Fold
Wegener’s evidence
Sea Floor Spreading
Causes of Plate Movement

4. Wegener’s Evidence
Wegener noticed that earth’s continents appeared to fit together like a puzzle. He hypothesized that they were once joined as a single landmass – Pangaea
Evidence:
Mesosaurus fossils in S. America and W. Africa – nowhere else in the world
Climate: tropical plant fossils found in Greenland, near the arctic circle. South African rock formations show evidence of ice sheet scratches
Geology: rock types in Brazil match those in W. Africa. Appalachian Mtns have limestone similar to Scotland’s Highlands

5. Pangaea

7. Earth remains the same size
Sea Floor Spreading
Scientists mapping ocean floor found huge underwater mountain ranges—Mid Ocean Ridges
Ridges form along cracks in the crust. Molten rock rises through crack, forms new crust, older material is pulled away from the crack
Drilling samples of sea floor reveal youngest rock is closed to the ridge, oldest is further away. Oldest ocean floor is younger than continental crust.
Ocean trenches found on sea floor. Oceanic crust sinks under continental crust and melts into asthenosphere.
Earth remains the same size

8. Magnetic Reversals
Minerals in magma rising through the mid ocean ridge align themselves with earth’s magnetic pole
As the rock cools, the minerals stay fixed in this position, like a compass
Earth’s poles periodically reverse. The “stripes” of rock along the ocean floor record these reversals.
N S N S N S N N S N S N S N
S N S N S N S S N S N S N S

9. Causes of Plate movement label: convection currents, ridge push, slab pull