Continental Drift and Plate Tectonics

Continental Drift

developed in the early part of the 20th century, mostly by Alfred Wegener

Alfred Wegener

Continental Drift is developed in the early part of the 20th century

Pangaea

all of Earth’s continents were once pat of this enormous, single landmass

Pangaea

existed about 240 million years ago and began breaking up about 200 million years ago

Pannotia and Rodinia

two other supercontinents

Pannotia

formed about 600 million years ago

Rodinia

existed more than a billion years ago

Place Tectonics

scientific theory of the large-scale motion of seven (7) large plates and movements of larger number of smaller plates

7

number of large plates that was theorized to be in motion

Plate Tectonics

began between 3.3 to 3.5 billion years ago

Plate Tectonics

average tectonic plate thickness in the lithosphere is about 100km

3.3 to 3.5 billion years ago

how long ago did the Plate Tectonics began to move

100km

average tectonic plate thickness in the lithosphere

1. South American Plate

2. Indo-Austrian Plate

3. Antarctic Plate

4. African Plate

5. Eurasian Plate

6. North American Plate

7. Pacific Plate

7 major tectonic plates

43, 600, 00 sq km

sq km of South American Plate

58, 900, 000 sq km

sq km of Indo-Australian Plate

60, 900, 00 sq km

sq km of Antarctic Plate

61, 300, 000 sq km

sq km of African Plate

67, 800, 000 sq km

sq km of Eurasian Plate

75, 900, 000 sq km

sq km of the North American Plate

103, 300, 000 sq km

sq km of the Pacific Plate

1. Oceanic Plates

2. Continental Plates

types of Tectonic Plates

Oceanic Plates

made of oceanic crust

Oceanic Plates

composed mostly of magnesium and silicon minerals

Continental Plates

made of continental crust

Continental Plates

composed mainly of aluminum and silicon materials

1. Transform Boundary

2. Divergent Boundary

3. Convergent Boundary

boundaries of Tectonic Plates

Transform Boundary

occur between plates which move past each other by sliding

Transform Boundary

plates gets minimal damage in this type of boundary

Transform Boundary

locations of these boundaries are called FAULTS

Divergent Boundary

plates slide apart from each other

Divergent Boundary

moves in opposite directions

Divergent Boundary

often occurs in seafloors, resulting to a new one

Divergent Boundary

volcanic activity produces a mid ocean ridge and small earthquakes

Convergent Boundary

plates move against each other

Convergent Boundary

one plate goes underneath another plate

Convergent Boundary

volcanoes and mountains are formed at these boundaries

Mantle convection

this drives the plate tectonic or the movement of the plates

1. Hot mantle rises at the ridge axis, creating new ocean crust.

2. The top of convection cell moves horizontally away from the ridge crest ,as does the new seafloor

3. The outer limbs of the convection cells plunge down into the deeper mantle, dragging oceanic crust, at the deepsea trenches

4. The material sinks to the core and move horizontally.

5. The material heats up and reaches the zone where It rise again.

the process of mantle convection on the movement of plates