What is the Continental Drift Theory?

Continental Drift Theory Alfred Wegner, 1915 The continents were once a super-continent called Pangea Panthalassa – ocean that surrounded pangea **** Was not originally accepted b/c people didn’t understand how such large masses of land could move. Pangea drift sequences

Evidence for Continental Drift 1. Continents fit together like puzzle pieces – Africa & South America look like they fit together 2. Matching Fossils on opposing continents Ex: Mesosaurus fossils found on the East Coast of South America and West Coast of Africa 3. Matching Rocks on the coasts of opposing continents ex: gems found in S.A. and Africa 4. Matching Mountain Chains4. Matching Mountain Chains Ex: Appalachian mtns in US match Caledonian in Europe 5. Evidence of Climate changes Currently cold locations have evidence of once warm climates and currently warm locations have evidence of once cold locations

Evidence of Warmer Climates  Areas were once in a warmer location if Coal deposits or Coral Reefs are found.  Coal deposits are found in Alaska and Antarctica  Since Coal is made from plant remains that have decayed in warm moist environments, this indicates that Alaska and Antarctica was once in a warm moist climate zone (near the Equator)  North America on the Equator North America on the Equator  Antarctica on the Equator shifting to the South Pole Antarctica on the Equator shifting to the South Pole

Coral Reefs Corals are warm water organisms, if fossils of corals are found that indicates the fossil location was once closer to the equator a warm climate zone. Vermont has the oldest known Coral Reef and Vermont is a Cold climate zone Vermont has the oldest known Coral Reef and Vermont is a Cold climate zone

Evidence of Cold Climates in Current Warm Zones Evidence of Glaciers in warm zones Ex: Northeast of South America Evidence of Glaciers in warm zones Ex: Northeast of South America So South America was once closer to the South Pole Follow the continental through the climate zones Follow the continental through the climate zones