Presentation on theme: "Continental Drift What evidence do scientists have to support the fact that the Earth’s crust is continuously moving?"— Presentation transcript:
1 Continental DriftWhat evidence do scientists have to support the fact that the Earth’s crust is continuously moving?
2 1500s – Abraham OrteliusSaw that the coastlines of Africa and the Americas looked similarConcluded they must have once fit togetherBroke apart due to floods, earthquakes and volcanoes
3 1800s – Eduard SuessStated that the southern continents were once a single landmass called GondwanalandNorthern continents called Laurasia
4 1900s – Alfred Wegener Continental Drift Hypothesis that Earth’s continents were joined as a single landmass that broke apart about 200 million years ago (mya)Known as PangaeaContinents slowly moved to their present locations
6 Evidence from FossilsSimilar fossils of several different plants and animals that once lived near each other found on widely separated continentsLand animals did not swim across ocean, so there had to be a land connection between continents
7 Evidence from Rock Formations Similarly, rock formations are similar on distant continentsFor example, rock types found in Appalachian Mountains similar to those found in Greenland and Europe
9 Climatic EvidenceCoal deposits in Antarctica indicate that the climate was much warmer in the pastMust have been located closer to the equator before it drifted
10 Flaws in Continental Drift Theory Wegener’s theory of continental drift had some notable flaws:Not able to explain what force was large enough to move such large pieces of earth over great distancesNot able to explain how the ocean basins were not shattered, despite solid landmasses crossing through them
11 Review Questions What does Pangaea mean in Greek? What was Ortelius’ contribution to Continental Drift?Who is credited with the theory of Continental Drift?List and describe the three main evidences for Continental Drift.What is one major flaw in the theory of Continental Drift?