A Rock’s JourneyFirst Steps

Igneous RocksBefore rocks, there was

◦Magma Molten crystals that flow like a liquid.

After these molten mineral grains cool, they form a specific type of rock called◦ Igneous rocks

These rocks come in three different and unique forms◦ Intrusive◦Extrusive◦Volcanic Glass

Igneous RocksIntrusive rocks

◦Form in the depths of the Earth over thousands of years

This time allows them to form very◦Large mineral grains

Igneous RocksWhen magma reaches the

surface and cools there, it forms◦Extrusive rocks

With very ◦Small ◦mineral grains

Igneous RocksThe violence of volcanoes causes

mineral grains to be thrown into the air where they cool so quickly they have◦Little or no◦Mineral grains

These rocks are called ◦Volcanic glass rocks

Igneous RocksAlthough similar in general shape

and structure, these three types have different “races” within them:◦Basaltic◦Granitic ◦Andesitic

Igneous RocksBasaltic rocks are

◦ Dense, dark-colored rocks◦ Formed from magma that contains lots of the elements

Iron and magnesium

In opposition, granitic rocks are◦ Light colored rocks ◦ With a ◦ Lower density◦ Than basaltic rocks because it contains a lot of the

compound silica (SiO2)Finally, there are those rocks which find

themselves with a bit of basaltic and a bit of granitic properties; these rocks are called◦ Andesitic

Igneous Rocks

Igneous Rocks

Metamorphic RocksOnce rocks form solid and strong,

they must face the perils of this earth. Those rocks that face the most extreme conditions of earth form brilliant rocks that are even stronger than before.

These rocks are called◦Metamorphic rocks

Metamorphic RocksThe rock that forms into the

metamorphic rock is called the ◦Parent rock

Metamorphic RocksThe same ingredient mineral

grains take on many forms depending on the amount of ◦Heat and/or pressure◦they experience

Metamorphic Rocks

Forces experienced by rocks can come from either the ◦Weight of the Earth

pressing down on the rocks◦The extreme temperature

created near the Earth’s core

◦Or the contact of the rocks with hot lava, also called magma

Metamorphic RocksThese powers force the mineral

grains to flatten and move positions

If the mineral grains form into layers, the new metamorphic rock is called a ◦Foliated rock

If, however, they move into random positions, they are called◦Non-foliated rocks

Metamorphic RocksFoliated Non

foliated

Offspring becoming Parents

How metamorphic rocks are formed

Increasing Pressure & Temp

Categorizing Metamorphic Rocks

Sedimentary RocksRocks formed when fragments of

other rocks come together to form a new rock

Sedimentary RocksThree types of Sedimentary

Rocks◦Detrital◦Chemical◦Organic

Sedimentary RocksDetrital Rocks

◦Steps of Creation 1. Rock broken

Weathering and Erosion 2. Compaction

Squeezed together 3. Cementation

Water drips between and solidifies

Sedimentary RocksClassified by size and shape

Sedimentary RockChemical Sedimentary

◦Rocks from solution

Limestone

&

Rock Salt

Sedimentary RocksOrganic sedimentary rocks

◦Made from once living material

Sedimentary RocksAs humans do, some rocks will break up

with their partners and form new bonds with new partners. These new blended families are called sedimentary rocks. They form from the broken, shattered pieces or rocks and shells, called sediment, that have been torn from their parent rocks by harsh wind and raging water. These blended families come in three very different categories: detrital, chemical, and organic.

Sedimentary RocksThe most common form is when pieces of

sediment are forced together under pressure to form detrital rocks. This process occurs in three stages. First, the rock is broken down by weathering and erosion, which is the movement of weathered materials. Second, the sediments get closer and closer through a process called compaction. Finally, new water joins the mix and solidifies the bonds through cementation. These rocks are classified by the size and shape of their sediments.

Sedimentary RocksLike people of the same race, rocks of the

same type are still vastly different from each other. Out of solution come chemical sedimentary rocks. These rocks form when pieces of sediment that were dissolved in water come together and form a solid rock. Two examples of these rocks are limestone and rock salt. The rocks that aren’t really rocks are called organic sedimentary rocks because they are made of once-living material. Two examples of these rocks are coal and chalk.

Rock CycleHow rocks recycle

Rock Cycle