The Sea Floor

Continental vs. oceanic crust

What is Continental Drift?

• The idea that the plates are floating and moving around on a liquid mantle.

Evidence of Continental Drift and Plate Tectonics

1. Discovery of Mid-Ocean ridges

2. The fact that the earth fits together like a puzzle.

3. Similar species found on different continents

4. Deep sea rock much younger than continental rock. Why?

5. Distribution of earthquakes and volcanoes

6. Magnetic anomalies on the sea floor

Fossils found on high on mountains

All this combined led to the current theory of plate tectonics. We are

moving right now.

Direction of plate movement

Three types of plate movement

• 1. Diverging boundary

• 2. Converging boundary

• 3. Transform boundary

Diverging Boundary – mid ocean ridge

Converging Boundary

• Two Types– Oceanic crust to continental crust – subduction

zones – Continental crust to Continental crust

Oceanic crust to continental crust – subduction zones

Continental crust to Continental crust

Transform Boundary

San Andres Fault

Seamount

Island Arc Formation

Atolls

Atoll formation

Continental Margins

Mid Ocean Ridges

Hydrothermal Vents