The Rock CycleNo ….

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

SO…. Rocks are loose combinations of crystals of any variety of minerals

Do we have samples?

• Crystals…. a solid object/piece of inorganic substance having a definite internal structure and characterized by identifiable geometric patterns

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 livingthings

– Rocks broken down intosediments• Erosion

– Sediment is transported bywind, 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 gluedtogether 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?