Lecture 5 - Plate Tectonics (GSCI 160)

Fifteen vocabulary flashcards covering key terms from the Plate Tectonics lecture.

Convergent Boundary

A plate boundary where two plates move toward each other, often leading to subduction, mountain building, and earthquakes.

Subduction Zone

A region where one plate sinks beneath another into the mantle, usually involving oceanic crust and triggering volcanism on the overlying plate.

Oceanic Crust

Crust composed mainly of Fe-bearing basalt; denser than continental crust and prone to subduction.

Continental Crust

Crust made largely of granitic rocks; less dense than oceanic crust.

Lithosphere

The rigid outer shell of the Earth, including the crust and upper mantle, which moves on the asthenosphere.

Asthenosphere

The partially molten, weak layer beneath the lithosphere on which tectonic plates move.

Hydrated Minerals

Minerals formed or altered by the addition of water during subduction or hydrothermal processes.

Serpentinite

Hydrothermal alteration product of basaltic oceanic crust, rich in serpentine minerals (Mg, Fe, Ni, Al, Zn, Mn).

Hydrothermal Alteration

Process by which seawater-derived fluids alter rocks at mid-ocean ridges, adding water and minerals.

Mid-Ocean Ridge

Underwater mountain ranges where new oceanic crust forms from upwelling magma.

Volcanic Arc

A chain of volcanoes formed on the overriding plate above a subduction zone.

Wadati-Benioff Zone

A zone of deep earthquakes that occur as the subducting plate descends and interacts with the overriding plate.

Trench

A deep elongated depression at a subduction zone marking where one plate descends.

Continental-Continental Convergence

Collision between two continental plates resulting in large mountain ranges with little to no volcanism.

Wilson Cycle

The cyclical sequence of plate tectonic evolution: rifting, subduction, collision, mountain building, and breakup of continents over time.