Transcript of Our Earth. What do you think the earth looked like long ago?
- Slide 1
- Our Earth
- Slide 2
- What do you think the earth looked like long ago?
- Slide 3
- Do you think the map looked exactly the same?
- Slide 4
- Could the continents have been closer together?
- Slide 5
- Alfred Wegener A scientist who believed the continents used to
be close together. He studied the world map and noticed that the
continents could fit together like puzzle pieces.
- Slide 6
- Theory of Continental Drift Wegeners belief that the continents
move.
- Slide 7
- Pangaea 1 supercontinent All the landmasses combined About 250
million years ago
- Slide 8
- What was the evidence for Pangaea? Geologic Fossils
Glacial
- Slide 9
- Geological Similar rocks and mountains found on the coast of
Southwest Africa and Eastern South America.
- Slide 10
- Fossils are the remains from once living things. The same
fossils were found on the coasts of continents that fit together.
Fossils
- Slide 11
- Glacial Glacial deposits (sediments) are found on continents
that could have fit together.
- Slide 12
- Critics Many scientists did not believe Wegener because he
couldnt explain what force moved continents.
- Slide 13
- Between the 1950s-1960s, the Theory of Plate Tectonics was
developed. This theory stated that continents are part of moving
tectonic plates. Evidence of seafloor spreading helped prove this.
Theory of Plate Tectonics
- Slide 14
- Tectonic Plates Pieces of earths crust Found on the
lithosphere. 2 types: a.)oceanic b.)continental
- Slide 15
- Seafloor Spreading The widening of the ocean. New oceanic crust
is formed through volcanic activity.
- Slide 16
- Pangaea Song