Rocks (Chapter 7c)

igneous

rock formed from magma or volcanic lava

sedimentary

rock that forms when layers of sediment and organic material harden

metamorphic

rock formed by heat and pressure deep below the earth's surface

rock

a hard, natural substance made of one or more minerals

Examples of sedimentary rock

limestone, shale, conglomerate

Examples of igneous rock

granite, obsidian, pumice

Examples of metamorphic rock

marble and slate

the Flood

Important historical event that changed the earth's crust

magma

hot, melted rock material beneath Earth's surface

Foliated rocks

metamorphic rocks that break easily into flat sheets or layers

Non-foliated rocks have…

metamorphic rock that is NOT banded or layered; breaks into sharp pieces

coal

a rocklike substance that forms from decayed plant matter

How geologist classify rocks

according to how they formed

intrusive igneous rock

forms when MAGMA cools and hardens UNDER the earth's surface

extrusive igneous rock

forms when LAVA cools and hardens quickly ON the earth's surface