Continental Drift/Seafloor Spreading

Continental drift/Seafloor Spreading.

Continental drift-Explain it. The gradual movement of the continents across the earth's surface through geological time.

Identify 4 evidences the helped prove the continents where moving and explain each one.

1. Puzzle pieces
2. Tropical glaciers scratches  

3. Mountain Minerals
4. Similar Fossils 


Seafloor Spreading-Explain it. The formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid-ocean ridges and its subsequent outward movement on either side.

Identify 2 evidences that helped prove the sea floor was growing and explain each one.

1. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid- ocean ridge is approached, and the sediment cover is thinner near the ridge.  

2. Magnetic Reversals is the 2nd proof. A much better fit between the rifted continents is apparent when the shape of the continental slop is used instead of the continent's shoreline. Detailed mapping of distinctive rock units that extend out to sea along the South American and African coasts and North American and British coasts has shown that they would converge perfectly if the continents could be fitted together.