4. Plate Tectonics (Student's Copy)

Plate Tectonics

The theory explaining the structure of the earth's lithosphere which is divided into tectonic plates that move on the asthenosphere.

Continental Drift Theory

The hypothesis that continents are in constant motion on the surface of the Earth.

Pangaea

A supercontinent that existed during the late Paleozoic and early Mesozoic eras, which began to break apart about 175 million years ago.

Divergent Boundary

A tectonic plate boundary where two plates are moving apart, often associated with mid-ocean ridges.

Convergent Boundary

A tectonic plate boundary where two plates collide, leading to subduction or mountain formation.

Transform Fault Boundary

A tectonic plate boundary where two plates slide past each other, causing earthquakes.

Subduction Zone

An area where one tectonic plate moves under another plate and sinks into the mantle.

Asthenosphere

The partially molten layer of the earth located below the lithosphere that allows for the movement of tectonic plates.

Oceanic-Continental Convergence

The tectonic interaction where an oceanic plate subducts beneath a continental plate, often creating volcanic arcs.

Mantle Plumes

Upwellings of abnormally hot rock within the Earth's mantle that can cause volcanic activity.

Slab-Pull

The force exerted by a sinking tectonic plate at a subduction zone, aiding the movement of tectonic plates.

Ridge-Push

The mechanism of plate movement caused by gravity acting on the elevated mid-ocean ridges.

Fault

A fracture in Earth's crust along which movement has occurred.

Glaciation Evidence

The geological evidence of glaciers that indicate climatic conditions in Earth's history.

Fossil Distribution

The presence of similar fossils across different continents, supporting the idea of continental drift.

Lithosphere

The rigid outer layer of the Earth, consisting of the crust and upper mantle, divided into tectonic plates.

Mid-Ocean Ridge

An underwater mountain range formed by tectonic plates moving apart.

Grabens

Blocks of the crust that have dropped down between two faults, often leading to rift valleys.

Earthquakes

Sudden shaking of the ground caused by the movement of tectonic plates.