Rock On!staff.katyisd.org/sites/bdjh6science/Documents/PLEASE SEE...BASALT OBSIDIAN RHYOLITE •Extrusive rock forms in 2 ways –Volcano shoots it out –Fissures (cracks in the earth’s

Rock On! Igneous Rock

Metamorphic Rock

Sedimentary Rock

All rocks are

made of

MINERALS!!!!

graphite quartz salt

• Minerals inorganic solid materials

found in nature. 4,000 different kinds

of minerals exist!

• Inorganic means not formed by

plants or animals.

• All minerals look and feel

different from one

another. You can use

physical properties to tell

different mineral apart.

gold silver

calcite

sulfur

How minerals form… • From melted rock inside the earth called magma

(reaches earth surface called lava) cools and

combines to form minerals.

lava

magma

Scientists classify rocks

by using two important

criteria

granite lead

marble salt rock The minerals that the rock is made of!!!!

•Determined by the shape, size, arrangement, and distribution of rock’s

mineral grains •Provides clues for how and where rock

formed

Glassy Texture Rocks have NO visible grains!

Obsidian

Rocks have small visible grains!

Fine-Grained Texture

Basalt

Shale

Rocks have large visible grains!

Course-Grained Texture

Granite

Gneiss

Rocks have small and large

visible grains!

Porphyritic Texture

Granite

Rhyolite

Rhyolite

Textures Glassy Course

Grained

Fine

Grained Porphyritic

Three Types of Rocks

Igneous Rocks

Sedimentary Rocks

Metamorphic Rocks

•Igneous means

•Igneous rocks form

when

and hardens

DIORITE OBSIDIAN

GRANITE

BASALT

Two Types of

Igneous Rock

Extrusive

Rock

Intrusive

Rock

Intrusive (inside) rock

that forms when magma

cools below earths surface.

• Takes a LONG time to

cool, so large grains form

• Usually course-grained

PEGMATITE

DIORITE

Extrusive (exit) rock that forms

when lava cools on the earths

surface.

• Cools very quickly, so only small

crystal may appear

• Usually have fine- grained texture

BASALT

OBSIDIAN

RHYOLITE

• Extrusive rock forms in 2 ways

–Volcano shoots it out

–Fissures (cracks in the earth’s crust where lava oozes out)

fissure

•Form as sediments

become compacted and

cemented together

• Sediments are pieces of rock, shells, minerals and grains.

3 types of sedimentary rock

• Clastic rock

• Chemical rock

• Organic rock

• Clastic rock forms when wind or water moves

fragments of other rocks and minerals close together.

• Minerals in dissolved water cement these particles

together. Weight of new sediments on top of the old

compress them even tighter.

Weight of

new sediment

Pressing on old

sediment

Clastic Sedimentary Rock

Conglomerate

Sandstone

Chemical rock

• rock formed when water high in mineral

content such as in oceans or geysers

evaporates leaving the sediments behind.

• NOT made from pre-existing rock

Chemical Sedimentary Rock

• Limestone

• Organic rocks rock that comes from

dead organisms that have been dead over

millions of years.

• Examples: coal, fuel

1 year

later

Bones break down

Turns into dust

10 years

later

More animals

Die dead animal

Particles slowly

Get stacked on top

Of each other

100 years later

1000 years

New animal

particles

Old animal

particles

Old

new

pressure

Organic rock is

made from

fossils (remains

or traces of once

living plants or

animals)

Organic Sedimentary Rock

• Coquina

Fossiliferous Limestone

•Metamorphic comes from “META” which

means changed and “MORPHOS” which

means shape

•Form when sedimentary, igneous or other

metamorphic rocks are exposed to intense

heat and pressure

• New rock can be changed to different kinds of rock by adding heat and pressure. The new type of rock formed is called metamorphic rock.

Heat and pressure

limestone marble

• 2 types of metamorphic rock

• Foliated rocks with visible layers

• Nonfoliated rocks with no visible layers

nonfoliated foliated

• Rock cycle constant changing of rock

from one type to another.