Rocks, Rock!

Mineral and Rock Vocabulary

Rock

• Rock is a solid mixture of crystals of one or more minerals

• Rocks are categorized into 3 types on how they are made

• Each rock in each category is classified (named) by its TEXTURE and COMPOSITION

Igneous Rock

• Definition: Igneous rock is rock formed when magma cools and solidifies into rock. (Rock from Volcanoes)

• Extrusive vs. Intrusive– Intrusive Rock- When magma cools slowly under the earths

surface- causing large grained rocks– Extrusive Rock- when magma erupts from a volcano it is

called lava, lava cools quickly causing fine (small) grained rocks

• Felsic vs. Mafic– MAFIC: Low silicon level rocks which are dark colored rocks– FELSIC: High silicon level rocks which are light colored rocks

Igneous Rock Examples- special features

Pumice Basalt

Granite

Gabbro

ExtrusiveGrain size-formed outside quickly

IntrusiveGrain Size-formed inside slowly

Felsic- Mafic

Obsidian

Review Time

• Turn to your neighbor and explain to him/her what igneous rock is, and what the 4 types of igneous rock are.

• How are rocks grouped (3 ways)

Quiz Time

• Which of the following best describes this rock

• A Extrusive Mafic• B Intrusive Mafic• C Extrusive Felsic• D Intrusive Felsic

Sedimentary Rock• Definition: Rocks that form when sediments

are compacted and cemented together• Sediments are small fragments of rock –like

sand• Rocks must go through several steps before

they become sedimentary– Weathering– Erosion– Deposition– Compaction and Cementation aka lithification

Sedimentary Rock Examples and special featuresClastic- rock

fragments

Chemical- minerals and water

Organic- Made from shells, skeletons, fossils and minerals

Conglomerate- large fragments

Sandstone medium sediment

Chemical limestone Fossiliferous limestone

Quiz Time

• What is the best description of this rock?• A Clastic Sandstone• B Clastic Conglomerate• C Organic fossiliferous limestone• D igneous rock

Review Time

• Turn to your neighbor and tell them the difference between sedimentary and igneous rock.

Metamorphic Rock

• Definition: Rock that forms when the texture and composition of preexisting rock changes due to heat or pressure.

Fast Five Quiz

• Go as quickly, and as safely as you can to the right corner. The following words are associated with what kind of rock?

• A Sedimentary Rock• B Metamorphic Rock• C Igneous (Extrusive)• D Igneous (Intrusive)

Energy and the Changing earth

• We talked about how energy changes in food pyramids and food webs, and how that affects living organisms. Refresh:

___________ _____________________________

• now lets talk about energy and how earth’s rocks are affected- what is chemical/mechanical energy?

Rock cycle

Decision Time

• Where and how can you see chemical/mechanical energy in this new system?

• Now that you have seen some examples of rocks, and you have seen the rock cycle. If you wanted to build a strong, long lasting monument to yourself for the world to see what type of rock would you use and why?

Weathering

• Definition: breakdown of rock into smaller and smaller fragments.

Mechanical Weathering

• Mechanical weathering: The breakdown of rocks by physical means- by ice, wind, water force, gravity, abrasion

Chemical Weathering

• Chemical weathering: the breakdown of rocks by chemical means into new substances- by soil, water, weak acids,

Erosion

• The removal and transport of sediment and material by wind, water or ice (glaciers)

Deposition

• Definition: Depositing sediments, or the laying down of sediments from movement.

Compaction and Cementation

• Definition: The squeezing and solidifying (gluing) of sediments together to finally become rock.

Magma