Rock Cycle Why Study Rocks? Rock Study Mato Tipila “Bear Lodge” Paha Sapa “Black Hills”...

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Rock Cycle

Why Study Rocks?

Rock Study

Ancient Societies

Rock StudyCultural History

Legends & Sacred Places

Mato Tipila“Bear Lodge”

Paha Sapa“Black Hills”

Badlands

3 Stages of Rocks

Categorized by the way they form

1. IGNEOUS

2. SEDIMENTARY

3. METAMORPHIC

Rock Cycle

SedimentaryIgneous

Metamorphic

Rock Cycle Simulator

http://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page01.cfm?chapter_no=investigation

Interactive Rock Cycle Animation

Gasses in Magma

SilicaIronSodiumPotassiumAluminumMagnesium

Water VaporOxygenCarbon DioxideNitrogenHydrogenSulfur Dioxide

Elements in Magma

8 Basic Rock Forming Minerals

OlivinePyroxeneAmphiboleOrthoclasePlagioclaseMuscoviteBiotiteQuartz

IGNEOUS ROCKSRock-Forming Process: Lava or Magma Cooling

ExtrusiveCools Quickly: PlutonicFine-Grained Crystals

IntrusiveCools Slowly: AphaniticLarge-Grained Crystals

IGNEOUS ROCKS

Andesite is a gray to black volcanic rock. It is generally erupted from stratovolcanoes as thick lava flows.

Basalt Lava - Basalt is a hard, black volcanic rock. Basaltic lava flows quickly and which allows volcanic gases to escape without explosive events.

IGNEOUS ROCKSObsidian is usually black in color though it can also be red or have a greenish tint. Obsidian is formed when the lava cools so quickly that crystals do not have time to grow. Obsidian fractures with very sharp edges. Native Americans use it to make knives, arrowheads, and other tools where sharp edges were important. Extrusive

Granite is a common intrusive igneous rock. Because it cools slowly crystals have time to form. The name granite comes from the Latin word granum which means “a grain” for the coarse grain crystalline structure of the rock.

IGNEOUS ROCKS - TEXTUREVesicles: Gas Pockets

Glassy:No Visible Crystals

Fine:Crystals < 1mm

Coarse:Crystals 1-10 mm

Very Coarse:Crystals > 10 mm

IGNEOUS ROCKS - COLOR

Felsic90% Light10% Dark

Mafic90% Dark10% Light

Andesitic50% Light50% Dark

UltramaficGreen

Igneous Rock Review

What is the Rock-Forming Process?

Igneous Rock Review

Rock-Forming Process Lava or Magma Cooling

Igneous Rock Review

Two Types of Igneous Rocks?

Igneous Rock Review

Two Types of Igneous Rocks 1. Extrusive 2. Intrusive

Igneous Rock Review

Two Types of Igneous Rocks 1. Extrusive 2. Intrusive

2 Igneous Rocks?

Igneous Rock Review

Two Types of Igneous Rocks 1. Extrusive or Plutonic 2. Intrusive or Aphanitic

4 Igneous Rocks1. Andesite 2. Basalt3. Obsidian 4. Granite

SEDIMENTARY ROCKSThree Unique Processes Results in Three Main Groups

Clastic Chemical Organic

Clastic Sedimentary RocksRock-forming Process: Erosion & Compaction - Cementation

Weathering: Wind, Rain, Moving Water, Freezing Water Breaks Rocks Into Smaller Pieces

Erosion: Combination of Weathering & Movement of Sediment

Sediments: The Smaller Pieces of Weathered Rocks

Deposition: Sediment Settled Out of Wind, Moving Water or Due to Gravity

Lithification: The Process of Sediment Changing to Rock

Compaction: After sediments are deposited - The weight of the sediments squeezes the particles together. When more and more sediments are deposited on top, the weight on the sediments below increases.

Cementation: Dissolved minerals fill in the spaces between the sediment particles. These liquid minerals act as glue or cement to bind the sediments together.

Waterborne sediments squeeze so tightly together that most of the water is pushed out.

Clastic Sedimentary Rocks

Erosion

Clastic Sedimentary Rocks

Conglomerate is made up of rounded pebbles cemented together.

Breccia is made up of angular pebbles cemented together.

Sandstone is sand grains cemented together into solid stone.

Siltstone is made from silt particles cemented together.

Shale is made from silt particles cemented together. It is similar to siltstone but with even finer grain size.

Chemical Sedimentary Rocks

Positive & Negative atoms crystallize into solid mineral crystals. This process is called precipitation. Precipitation can occur within an ocean, a lake, a cave, or where a hot spring flows out onto Earth's surface.

Rock-Forming Process: Chemicals Reactions Form Minerals in Water

Carbonates: Composed mainly of carbonate minerals. Dolomite Limestone.

Dolomite

Chemical Sedimentary Rocks

Evaporites: Evaporation leaves water enriched with calcium, sodium, and chlorine atoms – Which then precipitate from the water Halite or rock salt Gypsum

Siliceous: Composed of an exceptionally high amount of crystalline siliceous material, mainly the mineral quartz Chert

Organic Sedimentary Rocks

Rock-Forming Process: Organic Matter (Plants)

Lignite is black and has a crumbly consistency

Bituminous coal can be dull to shiny and black.

Sedimentary Rock Review

3 Main Groups of Sedimentary Rocks?

3 Main Groups of Sedimentary Rocks

Rock-Forming Processes for each Main Group?

Erosion & Compaction - Cementation

Chemicals Reactions Form Minerals in Water

Organic Matter

Sedimentary Rock Review3 Main Groups of Sedimentary Rocks

Erosion & Compaction - CementationChemicals Reactions Form Minerals in Water

Organic MatterExamples from Each Main Group?

Erosion & Compaction - CementationChemicals (Elements) Dissolved in Water

Organic MatterConglomerateBrecciaSandstoneSiltstoneShale

LimestoneDolomiteRock SaltGypsumChert

Rock-Forming Process: Heat & Pressure

Heat - Gravity Pulls Crust Downward- Increases Further Downward

Pressure

Hydrothermal Solution- Hot Steam Escapes from Mantle Carrying Dissolved Minerals - Dissolves Existing Minerals in Rocks & Deposits New Minerals - Recrystallization Alters the Rock’s Composition

- Energy Source for Chemical Reactions- Mantle- Friction- Increases Further Downward

Contact metamorphism

- Magma forces into existing rock- Heat bakes surrounding rock- Small, low-grade metamorphism

Metamorphic Rock Marble: Created from limestone that has been subjected to heat

Regional metamorphism

- Affects Large Regions- High-grade Metamorphism- Mountain-Building

Black Canyon of The Gunnison

Gneiss

Pegmatite

Foliated Non-foliated

Bands or LayersProgressing Through Stages of Metamorphism

One Mineral

Two Main Groups

Schist

Gneiss

Shale, Mudstone, Siltstone (Very Fine Grained)

Slate (Fine Grained)

Schist (Medium – Coarse Grained)

Granite, Igneous Rocks

Gneiss (Medium – Coarse Grained)

Textures

Limestone

Marble (Medium – Coarse Grained)

Quartz Sandstone

Quartzite (Medium – Coarse Grained)

What are the 2 groups?

Foliated Non-Foliated

What are the foliated stages?

Shale – Slate – Schist – Gneiss

What are the Non-Foliated rocks & why are they non-foliated?

Marble & Quartzite – They are composed of single minerals

Rock Cycle

SedimentaryIgneous

Metamorphic

Rock ReflectionCultural History

Legends & Sacred Places

Mato Tipila“Bear Lodge”

Paha Sapa“Black Hills”

Igneous Rock - Intrusive

Sedimentary – LimestoneMetamorphic - Granite

Sedimentary – Deposition & ErosionsFossils of Extinct MammalsMetamorphic - Shale

Badlands

References

http://www.rocksandminerals4u.com/igneous_rock_cycle.html

Rock Cycle Why Study Rocks? Rock Study Mato Tipila “Bear Lodge” Paha Sapa “Black Hills”...

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