the gradual movement of the continents across the earth's surface through geological time.

The theory that continents were once connected but have drifted apart

preserved remains or traces of animals, plants, and other organisms from the remote past.

the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side.

when all of Earth's major continents were once combined into one supercontinent.

the cool, rigid outermost layer of the earth, consisting of the crust and upper mantle; broken into segments called plates

the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

a long, narrow, deep depression in the ocean floor, typically one running parallel to a plate boundary and marking a subduction zone

refers to the pattern of alternating magnetic polarity stripes found on the ocean floor, created by the Earth's magnetic field reversing over time

long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma associated with seafloor spreading.

A circular movement of fluids caused by the rising of hotter, less dense fluid and the falling of cooler, denser fluid

A major geological process; occurs when continental plates of equal density converge, creating mountains

The boundary between two tectonic plates moving toward each other, resulting in volcanic activity when a denser oceanic plate subducts, or moves below, a continental plate or another oceanic plate

A place where two tectonic plates move away from each other

The theory that the crust is divided into large pieces called tectonic plates that slowly move on top of the mantle

A place where two tectonic plates slide past each other

a series of long, straight, parallel lines or grooves scratched onto the surface of a geological feature by rock fragments lodged in the base of a moving glacier

in undisturbed layers of sedimentary rock, the oldest layer is at the bottom, and the youngest layer is at the top

fossils used to determine the ages of rock layers

a volcano that produces exceptionally large and powerful eruptions

stationary locations on Earth where magma from the mantle rises to the surface