L4.3: Continental Drift Theory

• CONTINENTAL DRIFT THEORY

  ● Alfred Wegener suggested that 200 million years ago there was a supercontinent called Pangaea that started to drift apart into smaller continents.

  ● Pangaea → Laurasia & Gondwana → Modern World (7 Continents)
• Evidence of Continental Drift Theory

  ● Apparent Fit

  ● Ancient Climatic Similarities

  ● Fossil Evidence

  ● Geologic Structures
• ● Apparent Fit

  ○ Continents were once connected and have since moved apart. For instance, Africa and South America fit together like pieces of a jigsaw puzzle.
• ● Ancient Climatic Similarities

  ○ Glacial striations of ancient times and found that glaciers of the same period are located in Australia, South America, Africa, India, and Antarctica. Some of these countries don’t have subpolar climates that allowed glaciation.
• ● Fossil Evidence

  ○ Similar fossils of extinct plants and animals in rocks of the same age were found on different continents, which are now separated by large bodies of water.
• ● Geologic Structures

  ○ Several major mountain belts end abruptly at the continental margins but they are similar in age and structural style to mountains on the opposite sides of an ocean. When these oceans were closed by moving the continents back together, the ends of the mountain belts became joined into a single mountain belt.