Geology Plate Tectonics

# Geology Plate Tectonics

## Core Principles
The Earth's [LT] is fragmented into rigid plates floating on the plastic [AST]. Tectonic activity occurs primarily at plate margins.

## Boundary Types
1. [DIV]: Plates move apart; magma rises to form new crust (e.g., [MDR]).
2. [CON]: Plates collide. Oceanic-continental results in subduction zones and volcanic arcs; continental-continental leads to orogeny (mountain building).
3. [TR]: Plates slide laterally; significant seismic energy release without crustal destruction (e.g., San Andreas Fault).

## Driving Mechanisms
- Mantle Convection: Heat-driven circulation in the mantle.
- Slab Pull: Dense subducting oceanic plates pull the trailing plate.
- Ridge Push: Gravitational force sliding plates away from elevated ridges.

## Wilson Cycle
Describes the cyclical opening and closing of ocean basins, from continental rifting to seafloor spreading, subduction, and final collision.

## Geophysical Evidence
- Paleomagnetism: Magnetic reversals recorded in basaltic seafloor stripes.
- Hotspots: Stationary mantle plumes creating volcanic island chains.
- Seismic Tomography: Mapping mantle density/temperature variances.