ROCKS
Essential Questions What is a rock? Where do we find rocks? How are rocks classified? What is the Rock Cycle?
What is a Rock? Naturally-occurring mixtures of minerals, glass or organic matter.
Where do we find rocks? Where Do We Find Rocks? EVERYWHERE!!!
Rocks can be . . . Hard Soft Shiny Dull Smooth Rough One color Many colors
Classifying Rocks Rocks are divided into 3 groups based on how they were formed:
Igneous Rocks Igneous Rock is formed when magma or lava cools. Igneous rock can form: underground, where the magma (a hot liquid) cools slowly OR above ground, where the magma cools quickly.
Igneous Rocks formed underground (from lava or magma) usually have LARGE crystal grains (they cooled slowly)
Igneous Rocks formed above ground (from lava) usually have SMALL or NO crystals (they cooled too quickly)
Igneous Rocks
Sedimentary Rocks Sedimentary Rock is formed from sediments (rock fragments, mineral grains, animal & plant remains) that are pressed or cemented together. Sedimentary rocks form at or near the earth's surface at relatively low temperatures and pressures These sediments are moved by wind, water, ice or gravity. Sedimentary rocks are fossil-carrying rocks. They can be formed underwater, too, and can be made up of bits of shells and skeletons of sea animals.
Sedimentary Rocks
Metamorphic Rock Metamorphic Rocks are those that have changed due to intense temperature and pressure. Metamorphic rocks CHANGE FORM. Both igneous rocks and sedimentary rocks can change into metamorphic rocks Heat and pressure do not change the chemical makeup of the parent rocks but they do change the physical properties of those rocks. This rock has many layers.
Metamorphic Rock
The Life of a Rock Layers of sediment join together. Changes are made from pressure and heat. Melted rock cools and hardens
Once a rock is formed, does it stay the same rock forever? NO!
Rocks are continually changed by many processes, such as weathering, erosion, compaction, cementation, melting, and cooling Rocks can change to and from the three types
Rocks become bigger, and bigger, and bigger, and bigger . . . By earthquakes By volcanoes By heat and pressure
Rocks become smaller, and smaller, and smaller, and smaller. . . By erosion By wind By earthquake By floods By rain By mudslides
The Rock Cycle Song (Sing to the tune of "Row, Row, Row Your Boat") SEDIMENTARY rock Has been formed in layers Often found near water sources With fossils from decayers Then there's IGNEOUS rock Here since Earth was born Molten Lava, cooled and hardened That's how it is formed These two types of rocks Can also be transformed With pressure, heat and chemicals METAMORPHIC rocks they’ll be.
Let's Review
This rock is formed by cooling magma. IGNEOUS
This type of rock can be formed underwater This type of rock can be formed underwater. It is made up of bits of shells and skeletons of sea animals. SEDIMENTARY
This rock is formed by intense heat & pressure. METAMORPHIC
This rock is formed when tiny grains of sand become cemented together. SEDIMENTARY
This rock is formed by quickly cooled lava. IGNEOUS
IGNEOUS ROCKS ARE FORMED BY: Cooling Magma or Lava
Sedimentary rocks are formed when tiny grains of _______ become cemented together. SAND
Let’s Review A rock that has many layers, is flat, and comes apart easily is most likely which type? A. granite B. igneous C. metamorphic D. sedimentary D.