Plate Tectonics and Hot Spots

These flashcards cover essential vocabulary and concepts related to plate tectonics, geological processes, and rock types essential for understanding Earth science.

Plate Tectonics

The theory explaining the structure and movement of Earth's lithosphere, consisting of rigid plates that move over the viscous asthenosphere.

Hot Spots

Volcanic regions fed by underlying mantle that is anomalously hot relative to the surrounding mantle.

Isochron Dating

A method used to determine the age of an object by measuring the ratio of parent to daughter isotopes.

Half-life

The time required for half of the radioactive nuclei in a sample to decay.

Divergent Boundary

A tectonic plate boundary where two plates move away from each other, usually causing the formation of new oceanic crust.

Convergent Boundary

A tectonic plate boundary where two plates move toward each other, leading to subduction, mountain building, or volcanism.

Transform Boundary

A tectonic plate boundary where two plates slide past each other without creating or destroying lithosphere.

Seafloor Spreading

The process by which new oceanic crust is formed through the upwelling of magma at mid-ocean ridges.

Mafic Rocks

Igneous rocks that are rich in magnesium and iron, typically dark in color.

Felsic Rocks

Igneous rocks that are rich in silica and have a lighter color.

Lithosphere

The rigid outer layer of the Earth, consisting of the crust and upper mantle.

Asthenosphere

The ductile, upper part of the mantle just below the lithosphere, involved in tectonic plate movements.

Magnetic Anomalies

Variations in Earth's magnetic field caused by changes in the underlying geology, especially along mid-ocean ridges.

Rift Valley

A lowland region formed by the interaction of tectonic plates, often associated with divergent boundaries.

Volcano

A rupture in the Earth's crust that allows lava, ash, and gases to escape from below the Earth's surface.

Hypocenter

The point inside the Earth where an earthquake originates.

Epicenter

The point on the Earth's surface directly above the hypocenter of an earthquake.

Continental Rift

A region where the continental crust is being pulled apart, leading to rifting and the formation of new oceanic crust.

Thermal Convection

The movement of fluid due to differences in temperature and density, crucial for heat transfer in the Earth's mantle.

Pressure

The force exerted by a substance per unit area, crucial in determining melting points in geology.

Magnetite

A magnetic iron ore that can affect the magnetic properties of rocks.