So What Makes Igneous Rocks the Same, Anyway?

How are we related?

The story begins: Igneous rock gets it beginning in the

core of the earth- the hot magma Better known as Lava when it comes to the

surface

So just what is magma? Mixture of elements:

Silica Iron Sodium Potassium And others

The plot (magma) thickens As magma cools, its constituent

elements react chemically and form the BIG 8 - the rock forming minerals

These 8 make up the bulk of igneous rock.

The Bowen Reaction Series The big 8 are arranged in this series based

on the temperature at which they were formed.

Solidify at high temperatures- top of series; solidify at low temperatures- bottom of series

To see the Bowen Reactions Series

Constituent Percent of Total Volume

H20 67.7CO2 12.7N2 7.65SO2 7.03SO3 1.86S2 1.04H2 .75CO .67Cl2 .41Ar .20

Listing of gases and other chemicals found in magma

http://csmres.jmu.edu/geollab/Fichter/IgnRx/Introigrx.html

Coarse vs. Fine??Slow cooling large grainsLarge grains “coarse grained”/intrusive

“Phaneritic” is my

name!

GRANITE

Coarse vs. FineQuick cooling small grainsSmall grains “fine grained”/extrusive

My name is “Aphanitic”

RHYOLITE

Coarse vs. FineVery quick cooling no grains

GLASS

SCORIAOBSIDIAN

I’m sooooo popular The 2 most common igneous rocks on

the earth’s surface are Basalt and Granite.

I’m important to know too! MAFIC - dark colored

Ferro-magnesium minerals

Ex: olivine, pyroxene, amphibole, biotite

BASALT

FELSIC- light colored

Non ferro-magnesium minerals

Ex: Calcium plagioclase, Sodium plagioclase

GRANITE

Biotite Plagioclase

CLASSY IGNEOUS ROCKS Classification for igneous rocks is

primarily based on: Texture (grain size) Color/composition

Click this link to see a more descriptive chart.

We evolve too!!!!!!!!!

Fractionation Fractionation

Fractionation Fractionation

FractionationFractionation

Parent

Rock

(mafic)

Crystallization of

Magma

Melting of preexisting

rock

Intermediate

rock

Left -over rock

Felsic rockLeft over

rock

This process continues

until nothing is left to

be split into fractions.

http://csmres.jmu.edu/geollab/Fichter/IgnRx/disthtml.html

Formation of igneous rocks relies on plate tectonics.

I’m fractionatingDivergent plate

boundaries Parent rock from

earth’s interior fractionates to form mafic igneous rocks: basalt and gabbro

Convergent plate boundaries

Parent rock on the exterior returns to the interior, fractionates and forms intermediate rocks:diorite, and later may form felsic rocks: granite

Without igneous rock formation and fractionation, there would be no continents.

Thanks to:http://csmres.jmu.edu/geollab/Fichter/IgnRx/Ighome.html