1. Lesson 4 Alfred Wegener

3. How do mountains form? Theory 1: C ooling, contracting-Earth theory . Mountains formed on the Earth's crust as wrinkles form on the skin of a drying apple. But why are they not evenly spread? Surely the earth would have cooled down by now?

5. Tectonic theory People once thought that the oceans and the continents were formed by shrinkage from when the Earth cooled down after being formed. Alfred Wegener proposed something different. Consider Africa and South America: These continents look like they “fit” together. They also have similar rock patterns and fossil records. These two pieces of evidence led me to believe that there was once a single land mass. This is my TECTONIC THEORY.

6. Fossil Glossopteris leaf

8. Glaciation 300-180mya

9. Theory 2: Continental drift. Mountains formed when the edge of a drifting continent pushed into another, causing crumpl ing and fold ing. But isn’t the Earth made of solid rock? Wegener also noted that when you fit Africa and South America together, mountain ranges (and coal deposits) run uninterrupted across both continents.

13. 1. Vine says it is significant that Wegener was a ‘meteorologist’ rather than a ‘geologist’. a What is a ‘meteorologist’? b Discussing reasons for the rejection of the idea of continental drift, Vine mentions the fact that Wegener was a meteorologist, surveyor, & polar explorer. Why does Vine suggest this is relevant? 2 Why does Vine think Wegener made a mistake by trying to measure the rate of continental drift? 3 Why did most geologists believe Harold Jeffries when, in 1929, he said continents cannot move? 4 Why did the publication of Holmes’s textbook Principles of Physical Geography in 1944 have greater effect than the article he published in The Transactions?