Planet Earth Unit Review Flashcards

A set of vocabulary flashcards covering key geological terms, theories of Earth's structure, and types of rocks and processes identified in the Planet Earth Unit Review.

continental drift

a theory about Earth’s structure; the continents have slowly changed their positions over time

convergent boundary

an area on Earth’s crust where two plates are pushing against each other

converging plates

two or more plates colliding

core

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

crust

the thin, outermost layer of Earth

divergent boundary

an area on Earth’s crust where two plates are pulling apart from each other

diverging plates

two or more plates moving away from each other

earthquake

sudden and often destructive movement of an area of the Earth’s crust as a result of two plates sliding against one another; especially along a fault line

erosion

the process of moving rocks and sediment from one place to another

fossil

any trace or remains of once-living organisms

geological time scale

a scale that breaks prehistoric time into eras and periods and shows the approximate dates that scientists now have for the first appearance of each general group of organisms on Earth

igneous rock

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

mantle

the middle layer of Earth, located between the crust and the core, and made of rock

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

mineral

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

mountain

a large, naturally occurring formation of Earths surface that rises sharply above the surrounding area

plate

one of the large sections into which Earth’s crust is divided

plate tectonics

a theory about Earth’s structure; Earth’s crust is made up of very large pieces that are always moving slowly on the mantle

rock

a natural material composed of one or more minerals

rock cycle

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

sediment

loose material such as bits of rock broken down by weathering

sedimentary rock

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

seismic waves

the energy waves (either primary, secondary, or surface) that are released by an earthquake and travel outward from its focus/epicenter

seismologist

scientist who studies earthquakes

strata

the term for each of the layers within sedimentary rock

stratification

when sedimentary rock builds up in visible layers

subduction zone

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

volcano

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

weathering

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