The Rock Cycle
No ….
Yes…..
Rocks Defined
• Solid mixture of crystals of one or more minerals
SO…. What are “minerals” and “crystals”?
• Minerals = anything with a definite chemical compound and definite
structure and always inorganic (never was “living”) which are typically found
in the earth (ex quartz, calcite, feldspar….)
Rock Cycle Processes
Erosion
• Deposition
• Compaction and Cementation
• Metamorphism
• Melting
• Cooling
• Solidification
• Weathering
• Crystals…. a solid object/piece of inorganic substance having a definite
internal structure and characterized by identifiable geometric patterns
SO…. Rocks are loose combinations of crystals of
any variety of minerals
Do we have samples?
Rock Classification
• How they are formed
• Where they are formed
• Composition
– Minerals that make up a rock
• Texture
– Sizes, shapes, and positions of the grains
Value of Rock ‐ History
• Important to scientists
– Help answer questions about the history of earth
and the solar system.
• Record of what the Earth used to be
• Fossils
Value of Rock
• Natural resource
– Used as tools and weapons
(hammers, spears,knives)
– Used in buildings, roads, and monuments
Rock Cycle Processes
• Weathering
– Rocks attacked by weather
• Air, moisture, and living
things
– Rocks broken down into
sediments
• Erosion
– Sediment is transported by
wind, water, ice or gravity
Rock Cycle Processes
• Deposition
– Sediments settle to the bottom
• Compaction and Cementation
– Compaction
• Layers form on top of each other
• Air and water pushed out
– Cementation
• Loose sediments are glued
together by natural glue
Melting
– Rocks deep in Earth melt and become magma
• Cooling
– Magma cools
• Solidification
– Rock solidifies
Rock Cycle Processes
• Metamorphism
– Means changed form
– Increased heat and
pressure
– Changes a rock into a
metamorphic rock
Who can tell us what is happening at each star?