Chapter 10 - Rocks

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Chapter 10 - Rocks

• What can be learned by studying rocks
• We can learn mo better about earth.
• So what is a rock???
• Its a mixture of 1 or more minerals. Easy.

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The Rock Cycle

• Shows how any rock may be transformed from one
  type into another.
• Its a continuous process that causes rocks to
  change.

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Vocab terms

• Magma underground molten rock
• Lava above ground molten rock
• Crystallization formation of minerals from
  cooling magma/lava
• Weathering any process that breaks down rocks
  into smaller pieces (sediment)

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Vocab terms

• Erosion transportation of sediment
• Deposition accumulation of sediment
• Lithification compaction and cementation of
  sediment
• Metamorphism changing one type of rock into
  another by heat/pressure/chemicals

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Igneous Rocksfrom fire

• 2 main types
• Intrusive (large crystals)
• From magma
• Underground
• Cools and forms slowly
• Extrusive (small crystals)
• From lava
• Above ground
• Cools and forms quickly

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Igneous Rocks Classification

• 2 ways to classify igneous rocks
• Texture and composition
• Texture (4 types)
• Coarse grained slow cooling, large crystals
• Fine grained fast cooling, small crystals
• Glassy super fast cooling, glassy
• Porphyritic slow and fast cooling, has both
  large and small crystals

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Magma Groups

• Granitic (felsic)
• High in silica, light colored, low density
• Basaltic (mafic)
• Low in silica, dark colored, high density
• Andesitic (intermediate)
• Ultramafic

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Sedimentary Rocks

• Your teacher rocks!

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Sedimentary Rocks

• From (Latin) sedimentum settling
• Made from sediments
• 4 agents of erosion (transportation)
• Water
• Wind
• Glaciers
• Gravity

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Sedimentary Rock Classification

1. Clastic formed from sediment
2. Chemical formed from precipitation or
   evaporation
3. Biochemical (organic) formed from remains of
   once living organisms

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Clastic Sedimentary Rocks

• Conglomerate rounded pebble sized
• Breccia angular pebble sized
• Sandstone sand sized
• Siltstone silt sized
• Shale clay sized

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Chemical Sedimentary Rocks

• Crystalline limestone precipitates from ocean
  water
• Travertine precipitates in caves
• Chert/flint - quartz
• Gypsum precipitates from oceans, too
• Rock salt evaporated salt water

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Biochemical Sedimentary Rocks

• Fossil limestone fossil remains
• Coquina shells and shell fragments
• Chalk microscopic shells and clay
• Bituminous coal plant remains

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Metamorphic Rocks

• Means to change from
• 2 types of metamorphism
• 1. Contact
• - small areas from magma
• 2. Regional
• - large areas from mountain building

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Agents of Metamorphism

• Heat (temperature)
• Pressure (stress)
• Reactions in hot solutions (chemicals)

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Metamorphic Rock Classification

• Classified by texture and composition
• 2 textures
• Foliated - layered
• Nonfoliated not layered

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Foliated Metamorphic Rocks

1. Slate very thin layers from shale
2. Phyllite thin layers, sheen, wavy, from slate
3. Schist medium layers,shiny, micas, from
   phyllite
4. Gneiss distinct black white layers, from
   schist or granite

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Nonfoliated Metamorphic Rocks

• Marble shiny, fizzes in acid, H 3, from
  limestone
• Quartzite shiny, wont fizz, H 6 7, from
  sandstone
• Anthracite coal shiny, black, from bituminous
  coal
• The carbon cyclesee page 85