types of rocks. 1. explain how rocks can be formed? 2. what is the rock cycle? warm-up:
TRANSCRIPT
Types of Rocks
1. Explain how rocks can be formed?
2. What is the rock cycle?
Warm-Up:
Warm-Up:
Describe the texture and composition of the two igneous rocks.
A B
How to Classify a RockHow to Classify a RockRock - A naturally occurring, solid, mixture of one or more minerals or organic matter
3 Groups (based on formation): igneous, sedimentary, and metamorphic
Texture and composition give clues as to how rocks are formed, and are used to classify rocks
Composition – the type of material a rock contains
Texture – the size, shape and arrangement of the minerals/particles that make up a rock.
Rocks are always changing form in a cycle called the Rock Cycle
Web Links (also found on my website)
Rock Cycle Interactivehttp://www.learner.org/interactives/rockcycle/index.html
Rock Cycle Animations
http://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page02.cfm
Igneous RocksExtrusive rocks- formed by cooling lava
Texture:• glassy (obsidian)• porous (pumice)• fine-grained (basalt)
Intrusive rocks- formed by cooling magma
Texture: • coarse-grained (granite)
Formation of Extrusive Igneous Rock
Extrusive Igneous Rock
Formation of Intrusive Igneous Rock
Intrusive Igneous Rock
Yosemite N.P.
Obsidian…
Basalt…
Granite…
Course Grained Texture
Pumice…
Porous Texture
Sedimentary Rocks Formed by:
Weathering (breaking down of rock)
Examples of WeatheringMechanical Weathering
Root Action
Frost Action
Moss
Examples of Weathering
Chemical Weathering: Oxidation (rock exterior)
Sedimentary Rocks Formed by:
Weathering (breaking down of rock)
Erosion (movement of sediments)
Five Agents of Erosion
Gravity (Mass wasting)
Gravity (Mass Wasting)
Slumping
Soil creep
Five Agents of Erosion
Gravity (Mass wasting)Wind
Wind
Five Agents of Erosion
Gravity (Mass wasting)WindRunning water
Running Water
Yellowstone Canyon & River
Niagara Falls
Five Agents of Erosion
Gravity (Mass wasting)WindRunning waterGlaciers
Glaciers
Five Agents of Erosion
Gravity (Mass wasting)WindRunning waterGlaciersWaves
Waves
Australia
Five Agents of Erosion
Gravity (Mass wasting)WindRunning waterGlaciersWaves
Sedimentary Rocks Formed by:
Weathering (breaking down of rock)
Erosion (movement of sediments)
Deposition (collection of sediments)
Examples of Deposition
Lateral moraine
Cape Cod (spit)
Nile River Delta
Sedimentary Rocks Formed by:
Weathering (breaking down of rock)
Erosion (movement of sediments)
Deposition (collection of sediments)
Compaction & Cementation
Compaction & Cementation
Sedimentary Rocks (categorized by composition)
Clastic Rocks (rock fragments) • Conglomerates (pebbles) • Sandstones (sand) • Shales (mud & clay)
Organic Rocks (once living) • Ex: limestone(coral and shells), coal (plants)
Chemical Rocks (evaporation)• Ex: rock salt, limestone, geodes, gypsum
Clastic Sedimentary Rock…Conglomerate
Shale
Sandstone
Organic Sedimentary Rocks…
Coal (plant mateiral) Limestone (shell & coral)
Chemical Sedimentary Rocks…
Limestone
Gypsum rock
Geode
Metamorphic Rocks Formed by tremendous heat & pressure, and chemical reactions inside the crust.
Formed from all three rock types.
Types of Metamorphic Rock
Foliated (bands or layers) Ex: schist, slate, gneiss
Gneiss
Slate
Foliated texture
Unfoliated (no bands or layers) Ex: marble and quartzite
Types of Metamorphic Rock
Quartzite
Sedimentary Rocks
Metamorphic Rocks
Igneous Rocks
Sediments
Magma & Lava
Heat Pressure
Compaction &Cementation
W.E.D.
W.E.D.
W.E.D.
Melting
Heat Pressure
Cooling
W.E.D. = Weathering, Erosion, & Deposition
Closure:
Describe the texture and composition of the two igneous rocks.
A B
Warm-up / Closure:
1. In igneous rocks how is cooling rate and crystal size related?
2. Which rock type would you have the best chance of finding a fossil? Why?