Download ROCKS!!

ROCKS!!
What is a rock?
• Substance that is naturally occurring, solid, and is
made up of minerals.
• How are rocks and minerals different?
• Rocks are made from minerals. (Rocks are cookies,
minerals are chocolate chips)
Why do we study rocks?
• Rocks tell us a story about the earth’s history.
• Dinosaurs, pre-historic life
• The earth is constantly moving, shifting, and changing
What are the different types of rocks?
• Igneous
• Sedimentary
• Metamorphic
Igneous
• FIRE
• Form from the cooling and hardening of magma/lava
• Cools slowly below surface of the earth = LARGE crystals
• Cools rapidly above the surface = small crystals
Igneous Characteristics
• Large, visible crystals
• Glasslike
• Holes from air bubbling while cooling
Two Types of Igneous
Intrusive (Inside)
• Magma cools under the
surface
• Large Crystals
Extrusive (Outside)
• Lava cools quickly
• Small to no crystals
• Contains air bubbles
Examples of Intrusive Igneous
Examples of Extrusive
What is a sediment?
• Fragments of rock that have been broken down as a
result of weathering.
How do Sedimentary rocks form?
Form as sediments and minerals become packed and
cemented together.
Sedimentary Characteristics
• Appearance of sand, pebbles, rocks cemented together
• Layers
• Appearance of fossils
• Rough texture
Types of Sedimentary
Clastic (Sediment)
• Form from compacted
sediments
• Classified by size
Organic/Crystalline
• Evaporites
• Precipitates
• Bioclasstic Rocks
Clastic Sedimentary Examples
Organic/Crystalline Sedimentary Examples
How does a Metamorphic rock form?
• Form as rocks are changed due to exposure to intense
heat and/or pressure
Metamorphic Characteristics
• Stripes in thin, parallel, wavy lines (Foliation)
• Tiny crystals lined up in same direction
• Very hard (usually can scratch metal)
• Smooth texture
Types of Metamorphism
Contact
• A change in the rock by
heat from magma
Regional
• A change in a rock caused
by intense pressure
• Plate boundaries
Contact Metamorphism Examples
Regional Metamorphism Examples