According to the continental drift hypothesis, the continents have slowly moved over time to their current positions. Alfred Wegener first proposed this theory in 1912. Seafloor spreading provided insight into the mechanism of plate tectonics, with magma pushing the plates apart at mid-ocean ridges and subduction zones pulling them under. About 225 million years ago, nearly all land was part of the supercontinent Pangaea, which has since broken apart, forming the continents in their current positions.

1. Continental drift theory

2. According to the hypothesis of continental drift, continents have moved slowly to their current locations.Theory of continental was purposed by alferedwegner in (1912)

4. Mechanism for Plate TectonicsSeafloor Spreading provided insight to the mechanism for how the continents moved. The magma which pushes up at the mid-ocean ridge provides the new land pushing the plates, and the subduction zones gobble up the land on the other side of the plates.The mechanism was convection currents!

5. Thirteen plate on the world

6. About 225 million years ago , nearly all the land was united in one large land callledPangaea

7. Pangaea about 200 million years ago, before it began breaking up. The southern portion of Pangaea Gondwana, and the northern portion Laurasia.

8. The continents about 70 million years ago. Notice that the breakup of Pangaea formed the Atlantic Ocean. India’s eventual collision with Eurasia would form the Himalayan Mountains

10. The position of the continents today. The continents are still slowly moving, at about the speed your fingernails grow. Satellite measurements have confirmed that every year the Atlantic Ocean gets a few inches wider!

13. Sea flour spreadingAs the seafloor spreads apart at a mid-ocean ridge, new seafloor is created.

15. Plate tectonic explainEarthquakes Mountains volcanoes

16. Earthquakes and volcanoes occur mostly along or near trenches and mid-ocean ridges...

17. Mountain formation

18. Volcanoes

20. Thawaearthequakeekkakdanna

21. Evidence to support the theory

22. Continental drift fossil evidence

23. “Puzzle Pieces”Continents look like they could be part of a giant jigsaw puzzle

24. Distribution of fossils of several organisms supported The theory that the continents were once joined together

25. Francis Bacon (1561-1626) first noted how coasts of Africa and South America fit.

26. Mesosaurus, a fresh water reptile that couldn’t swim across the open sea

27. Sequence of RocksSame rock patterns found in South America, India, Africa, Antarctica and Australia

28. Mountains in South America and Antarctica are believed to have formed as part of the same mountain chain.

29. Ancient ClimatesTropical plant remains (coal deposits) found in AntarcticaGlaciations in Africa, South America, India, and Australia during the same time

30. CoalDeposits found inAntarctica.Coal requires a warm, lush climate ===>What’s Antarctica like today? ===>

31. Glossopteris, a seedfern whose seeds are too large to be carried far by wind

32. Fossils of Glossopteris are found in Permian rocks of South Africa, India, Australia, South America, and Antarctica—all regions that were once part of Gondwanaland.

33. Problems With The TheoryNo mechanism for movement of continents

34. Wind and currents could possibly move fossils