Q2 Earth + Rock Cycle Test

Crust

made of rigid rock; includes continental and oceanic crust; top of the lithosphere

Mantle

semi-solid layer below crust; makes up most of Earth’s volume; convection currents occur here

Outer Core

liquid iron and nickel; generates Earth’s magnetic field

Inner Core

solid iron and nickel; hottest and densest layer due to immense pressure

Lithosphere

crust and uppermost mantle; rigid and broken into tectonic plates

Asthenosphere

semi-solid layer beneath lithosphere; allows plates to move

Convection Currents

circular motion in the mantle caused by heat from the core driving plate movement

Oceanic Crust

dense, thin, basaltic crust found under oceans

Continental Crust

less dense, thicker, granitic crust forming continents

Plate Tectonics

the theory that Earth’s lithosphere is divided into plates that move due to mantle convection

Convergent Boundary

where plates collide; can form mountains or subduction zones

Divergent Boundary

where plates move apart; magma rises forming new crust (mid-ocean ridges)

Transform Boundary

where plates slide past each other; causes earthquakes

Subduction

when denser oceanic crust sinks beneath lighter continental crust

Rock Cycle

process describing how rocks change from one type to another over time

Igneous Rock

forms when magma or lava cools and solidifies

Intrusive Igneous Rock

forms inside Earth from slowly cooled magma; large crystals

Extrusive Igneous Rock

forms on Earth’s surface from quickly cooled lava; small crystals

Sedimentary Rock

forms from compaction and cementation of sediments

Sediments

broken pieces of rock, mineral fragments, or organic material

Metamorphic Rock

forms when existing rocks are changed by heat and pressure

Regional Metamorphism

large-scale metamorphism caused by tectonic forces and pressure

Contact Metamorphism

local metamorphism caused by nearby magma heat

Fossils

remains or traces of organisms found in sedimentary rocks

Basalt

an extrusive igneous rock found in oceanic crust

Granite

an intrusive igneous rock found in continental crust

Marble

a metamorphic rock formed from limestone

Gneiss

a metamorphic rock formed from granite

Sandstone

a sedimentary rock formed from compacted sand grains

Shale

a sedimentary rock formed from compacted clay or silt

Limestone

a sedimentary rock formed from shells or organic material