Lecture Notes on Alfred Wegener and the Theory of Continental Drift

Introduction

• Observations of continental shapes reminiscent of puzzle pieces.
• Notable example: Eastern coast of South America and Western coast of Africa.

Alfred Wegener

• German meteorologist who proposed a radical idea: continents are moving.
• Introduced the concept of a supercontinent named Pangaea.
• His theory is known as Continental Drift.

Evidence for Continental Drift

1. Apparent Fit of Continents

• Coastlines of continents appear to fit together like puzzle pieces.

2. Fossil Correlation

• Mesosaurus fossils found only in southern South America and Africa.
  • Freshwater reptile; could not have crossed the Atlantic Ocean.
• Similar unique fossil distributions for other species (e.g., Cynognathus, Glossopteris, Lystrosaurus).
• Reassembly of continents shows logical distribution of these fossils.

3. Rock and Mountain Correlation

• Similar types and ages of rocks found in northeastern USA and UK/Northern Scandinavia.
• Suggests that these rocks were once part of the same landmass.

4. Paleo Climate Data

• Evidence of glacial striations found in currently warm areas (e.g., Amazon, Central Africa).
  • Indicates these areas were once closer to the poles.
• Bituminous coal deposits made from tropical plants found in currently frigid areas.
  • Suggests these areas were once tropical and located near the equator.

Conclusion of Wegener's Theory

• Wegener's four pieces of evidence solidified the theory of continental drift.
• Despite the strong evidence, he could not explain the force behind continental movement.

Wegener's Death

• Died in November 1930 during a research expedition in Greenland.
• His body was discovered months later; a cross marks his death site.

Legacy

• Wegener’s ideas were initially rejected but laid groundwork for modern geology.
• He is recognized as a pioneering figure in understanding Earth's geological processes.