Earth Science 8

Cementation

The gluing together of sediment by new miineral crystals

Compaction

The squeezing of sediment by the weight of overlying layers

Continental Crust

Crust that lies beneath a continent

Continental Drift

The movement of continents around the surface of the Earth

Convergent Boundary

A place where two tectonic plates move towards each other

Crust

The outermost layer of the Earth

Divergent Boundary

A place where two tectonic plates move away from each other

Earthquake

The sudden shaking of Earth’s surface

Erosion

The wearing away and removal of rock

Fossil

The remains or traces of an ancient organism preserved in rock

Geologist

A scientist who studies the earth

Hotspot

An unusually hot part of the mantle where volcanoes can form

Igneous Rock

Any rock formed by the cooling of magma or lava

Inner Core

The innermost layer of the Earth

Lava

Hot liquid located above the Earth’s surface

Lithosphere

The rigid outer part of the Earth, made of the crust and upper mantle

Magma

Hot liquid rock located below the Earth’s surface

Mantle

The thickest layer of Earth, between the core and the crust

Mid-ocean Ridge

An underwater mountain system where new oceanic crust forms

Metamorphic Rock

Any rock that has been changed by intense heat and pressure

Melting

A change of state from solid to liquid

Natural Disaster

An event in the natural world that causes death and destruction

Mitigation

An action that decreases the harmfulness of an event

Mineral

A natural substance usually found as crystals in rocks

Oceanic Crust

Crust that lies beneath an ocean

Ocean Trench

A deep balley in the ocean floor formed at a convergent boundary

Natural Hazard

An event in the natural world that endangers living things

Extrusive Igneous Rock

Any rock formed by the cooling of lava

Intrusive Igneous Rock

Any rock formed by the cooling of magma

Outer Core

The layer of Earth that lies between the mantle and inner core

Parent Rock

The original rock from which a metamorphic rock formed

Plate Boundary

A border between two neightbouring tectonic plates

Pressure

The amount of force applied over a certain area

Relative Dating

A method to determine if one rock layer is older or younger than another layer

Rock Cycle

The set of changes that turn one rock type into anotehr

Sediment

Small rock fragments such as mud, sand or gravel

Sedimentary Rock

Any rock formed when sediment is compacted or cemented

Tectonic Plate

A section of the crust and upper mantle

Weathering

The breakdown of rocks into small grains or soil