Rocks Pieces of the Earth’s crust.

Types of Rocks Igneous- Rocks that formed from the fiery depths of the Earth. They form from magma and lava. –Extrusive –Intrusive Sedimentary- Rocks that formed from the eroded sediment of other rocks through lithification (compaction, cementation) Metamorphic- Rocks that have been changed or morphed through heat and pressure

Igneous Rock Rock that forms from cooled magma or lava. Crystalline or glassy structure Extrusive or Intrusive Felsic- Thick viscous, silica rich, light colored Mafic- Hot, thin, fluid-like, often Iron rich, dark colored

Igneous Rock Igneous Rock Examples

Igneous Rock Structure depends upon freezing temperature of rock and rate of cooling Bowen’s reaction series –High freezing temperatures crystallize first –Depends upon composition –Discontinuous series- Mafic magma Olivine, pyroxine, amphibole, biotite, potassium feldspar, muscovite, quartz –Continuous series- Felsic magma Calcium rich, calcium/sodium rich, sodium rich

Bowen’s Reaction Series

Igneous Rocks Crystal size depends upon rate of cooling Fast cooling lava produces small crystals, or even no crystals (glassy) Slow cooling magma produces large crystals. When magma cools at different rates, large and small crystals may result creating porphoritic rock

Igneous Rocks Rock Families –Read about the 3 main types of rock families in your text. pgs –Summarize each type of igneous rock family in your notes

Igneous Families Granite (Felsic) Gabbro (Mafic) Diorite (Intermediate) Peridotite (Ultramafic)

Granite Family Mostly coarse grained felsic rocks that are generally light in color. Most granite family rocks cool slowly due to the thick sticky magma that they form from.

Gabbro Family Dark, dense coarse grained mafic rocks. Contain the minerals pyroxene, olivine, plagioclase feldspar, amphibole, and biotite.

Diorite Family A mixture of felsic and mafic rock. Darker than granites but lighter than gabbros.

Peridotite Family Dense coarse grained ultramafic rock. Contain the minerals olivine and pyroxene.

Sedimentary Rocks Sedimentary rocks form from fragments of other rocks producing clastic rocks. Through weathering and erosion, sediment is carried by wind and water. This sediment is eventually deposited. Deposition occurs when the moving water or wind slows down.

Sedimentary Rock Deposited material often gets sorted by size. Large sediment often only makes it part way down rivers. Small sediment makes it to the mouth of rivers. Fine silts and clays gets carried out to the middle of the oceans and lakes

Sedimentary Rock

Sedimentary Rocks Eventually material is formed into rock through lithification This sorting gives rise to different types of clastic rock such as –Conglomerate –Sandstone –Shale

Conglomerate

Sandstone The layering that is shown here is called stratification.

Shale

Sedimentary Rock Other types of sedimentary rock can be formed through chemical processes and organic material –Limestone (organic and chemical) –Halite (chemical) –Coquina (organic)

Limestone

Halite

Coquina

Sedimentary Rock Sedimentary Rock Examples

Metamorphic Rock Metamorphic rock is rock that has been changed over time due to heat and pressure. Crystals get squished and the texture becomes foliated Foliated metamorphic rocks have a layered or banded appearance that is produced by exposure to heat and directed pressure.

Metamorphic Rock Foliation Crystal are flattened Orientation becomes aligned

Metamorphic Rock Metamorphic Rock Examples Foliation process animation