Chapter 3 (continental drift and seafloor spreading)

Question 1

Alfred Wegner

Answer 1

Meteorologist by training
Developed continental drift hypothesis based on many geologic observations
Wrote “Origins of the Continents and Oceans”
Two Problems: No mechanism for how the continents moved and there was a prevailing assumption that the seafloor was static
But geologists accept many aspects of his theory today

Question 2

Plate tectonics

Answer 2

Explains movement of Earth’s lithospheric plates
Also explains, mountain range formation, earthquakes, volcanoes, seafloor topography, age of ocean floors
Developed by the ideas of continental drift and seafloor spreading

Question 3

Evidence Supporting Wegner’s Theory

Answer 3

1) The Fit of the Continents- continental shorelines match up
2) Age and type of rock in mountain belts on separate continents match up
3) Paleoclimate indicators: there is evidence from glacial till deposits and striations that if continents once joined, ice caps would have covered southern portions of many continents
The glacial evidence was found in areas that are tropical or subtropical regions today
4)