Igneous Rocks

What is the difference between magma and lava? Magma and lava are the same substance in two different forms. Magma is molten rock that is found beneath the earth's crust, while lava is what magma becomes once it reaches the surface and erupts from a volcano or crack in the earth

Igneous Rock Formation: Molten rock cools and becomes solid. igneous rocks form when magma below the surface slowly cools and hardens. igneous rocks form when lava (magma that has reached the surface of the Earth) quickly cools. Extrusive Igneous Rock Intrusive Igneous Rock

Igneous Rock Identification: Crystals formed from minerals are randomly arranged in igneous rocks. The presence of small crystals indicates that the rock cooled rapidly. The presence of large crystals indicates that the rock cooled slowly, deep within the crust and never reached the surface. Extrusive Igneous Rock Intrusive Igneous Rock

Common Igneous Rocks Granite

Common Igneous Rock Basalt

Sedimentary Rocks

Sedimentary Rock Formation: Layers of sediment are deposited at the bottom of bodies of water. The layers get compacted from the pressure of the layers above. As the water is squeezed out, the salts present in the layers of sediment begin to crystallize. These salts help act as glue to hold the particles together.

Sedimentary Rock Identification: Layers of sediment, easily scraped, and often crumble easily Sedimentary rock often contains fossils which are preserved remains of animals or plants.

Common Sedimentary Rock Sandstone

Common Sedimentary Rock Limestone

Metamorphic Rocks

Metamorphic Rock Formation: As the Earth moves, all types of rock can be pushed deep into the Earth. These rocks are exposed to extreme heat and pressure, causing the structure of the crystals and the texture of the rocks to change. They do not become liquid, but become somewhat molten.

Metamorphic Rock Identification: Hard rocks Foliated bands of fused minerals Crystalline structure with fused edges Movement of the Earth’s lithospheric plates cause the heating and squeezing conditions that form metamorphic rocks.

Common Metamorphic Rock Slate

Common Metamorphic Rock Gneiss

Sedimentation: The deposition of solid material from being suspended in a fluid (water) Compaction: Process by which overlying pressure from rocks and soil reduces the size and volume of sediments Cementation: The process of binding and hardening sediments into hard rock Vocabulary

Basalt: extrusive rock that cools quickly so crystals are not visible to unaided eye. Pumice: extrusive foamy volcanic glass with gas trapped inside. Gas escapes as the rock cools Igneous Rock

Obsidian: extrusive rock that cools so quickly that it doesn’t have time for crystals to form. Granite: intrusive rock that cools very slowly(hundreds of thousands of years) so crystals are large and visible.

Sedimentary Rocks Shale: composed of silt or clay that has been compacted or squeezed together to form a solid rock Sandstone: forms when grains of sand are cemented together to form solid rock

Limestone: forms as tiny pieces of shells and the skeletal remains of dead sea animals are cemented together. Coal: compressed vegetation Sedimentary Rocks

Metamorphic Rock Sedimentary: Limestone changes to marble Metamorphic: Phyllite changes gneiss Igneous: Granite can change to gneiss

Metamorphic change is caused by a.Heat b.Cold c.Pressure d.Both a and c

Sedimentary rock is changed into metamorphic rock when it a.Melts b.Weathers and erodes c.Is heated and put under pressure d.Cools

Which of these processes causes the breakdown of rocks? a.Weathering b.Cementation c.Layering d.Erosion

Melted rock outside the ground is known as? a.Lava b.Magma c.Sediment d.metamorphic

Which type of rock can change into metamorphic rock? a.Igneous rock b.Sedimentary rock c.Metamorphic rock d.All of the above

A type of rock that forms when hot, liquid rock hardens is called? a.Sedimentary b.Metamorphic c.Fine grained d.igneous