Rocks and Minerals

VocabularyPart 2

Sedimentary Rock• Definition: formed by weathering causing

sediments to build up in layers

• Usually found where there used to be a river, lake, ocean, sea, etc.

• p. 242

Notice the striping that goes across the rocks, that is formed by layers be set down in an ocean.

Fossil• Definition: records of past life on earth

• May be an imprint (mold), a bone, or the remains of something (cast)

• p. 244

Mold

• Definition: a hollow space in a rock with the shape of an animal or plant

• This is like when you make an imprint of your hand in clay or plaster

• Most often found in sedimentary rock

Cast

• Definition: hard sediments in the form of an animal or plant

• This is what happens when the animal or plant materials are replaced by minerals (all dinosaur bones)

Conglomerate

• Definition: sedimentary rocks made of small pebbles and dirt

• Think of pulling up a piece of concrete – with big stones and small pebbles and the tiny pieces that pull it all together

• Miss Veach has a good example, if you come ask nicely to see it – sorry, I couldn’t find a good picture.

Erosion• Definition: the process of soil being

washed away (by water)

• Related word: Weathering, the process of soil being blown away

• p. 264-266Erosion

Wea

ther

ing

Crystal

• Definition: a pattern of atoms repeated so many times it becomes large enough to be seen

Water crystals

Diamond crystal

Igneous Rock• Definition: formed when hot liquid rock

cools

• p. 246

Lava

• Definition: magma or hot liquid rock that pours out of a volcano

Magma• Definition: hot liquid rock found in the core

of the earth

• You can’t see a picture of it because once it comes out of the earth (where we could take a picture) it is called lava!

Volcano• Definition: an opening in the Earth where

magma comes onto the Earth’s surface (crust)

• p. 270

Iceland

Metamorphic Rock• Definition: formed by heat and pressure

• Starts as Igneous or Sedimentary rock that is changed by heat and/or pressure

• p. 248

When granite is put under heat and pressure it becomes gneiss – the wavy part shows the pressure it was under.

Rock Cycle

Sedimentary Rock

Met

amo

rph

ic R

ock

Ign

eou

s Ro

ck

Magmacools and hardens

weathering

weathering

extreme heat

extr

eme

heat

extreme heat

heat and pressure

heat and pressure

p. 248-249