Unit 4: Planet Earth Final Exam Review

Comprehensive vocabulary flashcards covering Earth's layers, rock types, plate tectonics, seismic activity, and fossil history based on the Unit 4 Planet Earth study guide.

Rock

A natural material composed of one or more minerals.

Mineral

An inorganic, naturally occurring solid material composed of one or more of the basic elements.

Igneous rock

The type of rock that is formed by the solidification of hot magma (classified as either intrusive or extrusive).

Sedimentary rock

The type of rock formed by the compacting or cementation of sediment.

Metamorphic rock

A type of rock made when high pressure and heat act on another type of rock and change it into a new form.

Crust

The thin, outermost layer of Earth that supports life.

Mantle

The middle layer of Earth, located between the crust and the core, made of rock and containing convection currents.

Core

The innermost part of Earth; made of iron and nickel in solid and liquid form.

Outer Core

The liquid metal layer of Earth that creates the Earth’s magnetic field.

Inner Core

The solid, very hot center of the Earth that remains solid due to extreme pressure.

Weathering

The process in which rocks are broken down and sediment is formed by mechanical, chemical, or biological means.

Erosion

The process of moving rocks and sediment from one place to another.

Sediment

Loose material such as bits of rock broken down by weathering.

Stratification

The process in which sedimentary rock builds up in visible layers.

Strata

The term for each of the layers within sedimentary rock.

Rock cycle

The naturally occurring process in which rocks continue to be changed and recycled over long periods of time.

Continental drift

A theory about Earth’s structure proposing that the continents have slowly changed their positions over time.

Plate tectonics

A theory about Earth’s structure stating that Earth’s crust is made up of very large pieces (plates) that are always moving slowly on the mantle.

Converging plates

Two or more plates colliding or pushing against each other.

Diverging plates

Two or more plates moving away from or pulling apart from each other.

Subduction zone

A place on Earth’s crust where high pressure pushes one very large piece of rock below another.

Seismologist

A scientist who studies earthquakes.

Seismograph

A technology used to help scientists understand how large or small an earthquake can be.

Epicenter

The place on the Earth's surface directly above the origin (focus) of an earthquake.

Seismic waves

The energy waves (primary, secondary, or surface) released by an earthquake that travel outward from its focus or epicenter.

Fossil

Any trace or remains of once-living organisms.

Relative dating

A method used to determine the age of fossils based on their position within surrounding rock layers.

Geological time scale

A scale that breaks prehistoric time into eras and periods showing approximate dates for the first appearance of general groups of organisms.

Burgess Shale

A famous fossil bed in the Canadian Rockies that preserves rare soft-bodied creatures from over $500$ million years ago.

Cambrian Explosion

A time period when many new types of life appeared quickly.

Sonar

Technology used by scientists to help visualize the bottom of the ocean.

Volcano

An opening in Earth’s crust that can release materials such as lava, smoke, and ash; classified as active or dormant.

Humus

The organic portion of soil.

Petrified

A type of fossilization where minerals replace the remains of an organism.