Rocks: mixture of minerals.

Classification by origin

Igneous Formed by the cooling and crystallizing of magma and lava.

Magma is intrusive. cools slowly. Forms large interlocking crystals.

Ex. Granite Most common rock. Contains: feldspar, quartz, and mica

Lava is extrusive. cools quickly. Small or no crystals. Ex. Obsidian Looks like black glass. Pumice: floats Basalt: black sand

Sedimentary Rocks Mostly made of Sediment from weathering and erosion

Sedimentary Rocks Formed by compacting and cementing of sediments Cementing: the binding together of particles or other things by cement. Compacting: compress/smush

Sedimentary Rocks Lithification: processing which sediments compact under pressure, expel fluids through and to gradually become solid rock. Compacting Cementing

Geologists classify sedimentary rocks based on formation Sediments are laid down in layers.

Clastic Made from Sediments- sand (Si02) clay, gravel, pebbles, and animal remains. Breccia

Bioclastic Organic in origin Large or visible living things Reacts to acid

Chemical/ Crystalline precipitated directly from solution. Ex. Rock Salt And Limestone (sometimes)

Examples-of Clastic Conglomerate- rounded pebbles, sand, etc. Sandstone- mostly sand Shale- packed clay

Chemical Limestone: if formed from a solution such as stalactites and stalagmites.

Chemical Rock salt: evaporation of sea water

Organic/Bioclastic Coal: plant matter carbonization Chalk: gradual accumulation of tiny calcite shells(microrganisims) Limestone: Composed mainly of skeletal fragments of marine organisms such as coral

Coquina- shell pieces Reacts to acid because of (CALCITE) COQUINA FROM FORT ST. AUGUSTINE

Metamorphic rocks Metamorphic rocks- “changed-over rocks” Changed by adding heat and pressure to existing rocks. Ex. GNEISS

All metamorphic rocks come from a parent rock(what it came from) Granite changes to Gneiss Sandstone changes to Quartzite Limestone changes to Marble-reacts to acid Shale changes to slate Shale or slate to schist Bituminous coal to Anthracite coal

2 Forms of Metamorphism Ex ; GNEISS Regional- by squeezing under heat and pressure over large areas of rocks Contact- melting and recrystalizing from the contact of magma Ex ; GNEISS quartzite

2 types of rock texture Ex ; GNEISS Foliated: rocks with visible parallel bands Formed: Regional metamorphisim Ex ; GNEISS

Foliated: Layers Ex. SCHIST

Nonfoliated ; no apparent banding Fromed: Contact metamorphism quartzite Nonfoliated ; no apparent banding Fromed: Contact metamorphism MARBLE