February 18, 2015 The rock cycle

The earth’s crust is made up of 3 types of rocks.

Type of Rock #1: IGNEOUS ROCK Formed from the cooling of molten rock (magma and lava) Under the Earth’s crust some rock has melted into magma When the magma is ejected out of the Earth’s crust through a volcano, it is called lava If magma cools and hardens beneath the Earth’s crust, it is considered plutonic igneous rock If lava cools and hardens on the Earth’s surface it is called volcanic igneous rock Plutonic igneous rock = intrusive Volcanic igneous rock = extrusive

Type of Rock #2: SEDIMENTARY ROCK Wind and water cause erosion to occur, breaking off pieces of rock and carrying them to a new location The pieces of broken rock, along with sand, pebbles, shells and plant matter gather together These gathered materials compress together into layers called sediment Sedimentary rock is softer than igneous rock and often contains fossils Most of the rock on the Earth is sedimentary

Rock Type #3: METAMORPHIC Rocks deep within the Earth are put through intense heat and pressure In time, this heat and pressure transform sedimentary and igneous rock into metamorphic rock Example: Limestone (sedimentary) turns into marble (metamorphic)

Activity: The Rock Cycle Components: Processes: Igneous Melting Sedimentary Weathering & erosion Metamorphic Heat & pressure Sediments Cooling Magma/Lava Compaction & cementation