Topic: Igneous Rocks Topic: Igneous Rocks

Igneous RocksIgneous Rocks

-- Lava – Lava – Magma – Magma –

CoolingCooling

SolidificationSolidification – – CrystallizationCrystallization – –

Igneous ClassificationIgneous Classification

Mineral composition -Mineral composition - Texture -Texture -

– --

ExtrusiveExtrusive Igneous Rocks Igneous Rocks

-- -- --

IntrusiveIntrusive Igneous Rocks Igneous Rocks

- - --

Animation: Igneous Rock Animation: Igneous Rock Environments of FormationEnvironments of Formation

http://www.classzone.com/books/earth_science/terc/content/investigations/es0603/es0603page05.cfm?chapter_no=investigation

Best Friend Pg 6Best Friend Pg 6

Scheme for Igneous Rocks for Scheme for Igneous Rocks for identificationidentification

Take out YOUR ESRT!Take out YOUR ESRT!

Identifying Igneous RocksIdentifying Igneous RocksIgneous Rock Names

Environment of Formation

Crystal Crystal sizesize

DescriptionGrain Size

Bubbles?Bubbles? Yes= Vesicular

Bubbles?Bubbles? No=Non-vesicular

ColorColorVery Light

LightNotVery LightNot Very Dark

DarkVery Dark

Neither Light nor Dark

Ligh

test

Darke

st

DensityDensityVery Low

Low DenseVery Dense

Medium Density

CompositionComposition

CompositionComposition

Felsic Rocks – Felsic Rocks – – --– --– --

MaficMafic– --– --– --

Finding The MineralsFinding The MineralsIdentify the rock.Unless you have other information,

work in the middle of the rock’s box.

This is the amount of Potassium Feldspar in the rock.

This is the amount of Quartz in the rock.

This is the amount of Plagioclase Feldspar in the rock.

Use tick marks on a scrap paper to measure the percentage.Potassium Feldspar 25%

Quartz 40%

PracticePracticeName a light-colored, fine-grainedrock with no bubbles.

Name a coarse-grained, dense rock & contains only Olivine.

Name a very light-colored, glassy, extrusive rock with bubbles.

FQ:FQ:Name the fine grain, vesicular Name the fine grain, vesicular igneous rock, with the minerals igneous rock, with the minerals

plagioclase feldspar, pyroxene and plagioclase feldspar, pyroxene and amphiboles.amphiboles.