THREE TYPES OF ROCKS

Thursday, January 19 How many different rock types are in this photo? How can rocks talk to us?

What is a rock? A substance that is naturally occurring, solid, and is made up of minerals How is a rock different from a mineral? Rocks are made from minerals

Elements Minerals Rocks

Why do we study rocks? A story about earth’s history Rocks tell us: A story about earth’s history Tell us about pre-historic life (Dinosaurs) The earth is constantly moving, shifting, and changing

Igneous Rocks Latin=“Fire” Igneous rock: forms when molten (melted) rock (magma) cools and hardens Basalt

Intrusive Igneous Rock cooling takes place slowly beneath Earth’s surface granite Cools Slowly=Large Crystals

Extrusive Igneous Rock Pumice Extrusive igneous: cooling takes place rapidly on Earth’s surface Obsidian=volcanic glass Cools Quickly=Small or no Crystals

IGNEOUS Cooling Magma Has big or small crystals (cooling time) “Fire” IGNEOUS Cooling Magma Has big or small crystals (cooling time) Granite, Obsidian, Pumice

Made from eroded particles Sedimentary Rock Sedimentary rock: Made from eroded particles Sediments are: Rock pieces Sand grains Shell fragments Limestone

How do sedimentary rocks form? Weathering: powered by sun Erosion: wind water, critters Sedimentation: small parts Deposit: layers Compact: Squished Cemented: glued

SEDIMENTARY Weathering Erosion Sedimentation Deposition Compaction Cementation Forms in layers, pieces glued together Sandstone, Limestone, Coal “Fire” IGNEOUS Cooling Magma Has big or small crystals (cooling time) Granite, Obsidian, Pumice

Metamorphic Rock To Change: butterfly Metamorphic rock: forms when any rock type is changed into a different kind of rock Changes due to great heat and/or pressure Foliated=lines Nonfoliated=no lines Gneiss

Metamorphic Rock To Change: butterfly Limestone + Heat and Pressure= marble Sandstone + Heat and Pressure= Quartzite

IGNEOUS SEDIMENTARY METAMORPHIC To Change: Weathering Erosion Sedimentation Deposition Compaction Cementation Forms in layers, pieces glued together Sandstone, Limestone, Coal Twisted and swirled by pressure and folding of the rock Marble, gneiss “Fire” IGNEOUS Cooling Magma Has big or small crystals (cooling time) Granite, Obsidian, Pumice

The Rock Cycle Rocks can change into new Rocks

The Earth Recycles Rock The rock cycle is an ongoing series of processes inside Earth and on the surface Slowly changes rocks from one kind to another Any type of rock can change into another type

How does this relate to plate tectonics? Plate movement drives the rock cycle Subduction (1 plate pushed under another plate) Re-melts rock into magma Mountain building Folding, faulting, uplift Exposes rock at the surface to be weathered and eroded

The Rock Cycle