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Rocks. Rocks. Mixture of two or more different minerals that have been: cemented together squeezed and heated together melted and cooled together . The Rock Cycle. The diagram of the rock cycle shows how rocks change slowly over time. Types of Rocks.
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Rocks • Mixture of two or more different minerals that have been: • cemented together • squeezed and heated together • melted and cooled together
The Rock Cycle • The diagram of the rock cycle shows how rockschange slowlyover time.
Types of Rocks 1. Igneous 2. Metamorphic 3. Sedimentary
1. Igneous Rocks “Igneous” comes from Latin for “fire” • Most igneous rocks are produced deep underground by the coolingandhardeningof magma (melted rock). 1. Granite 2. Obsidian 3. Pumice
Formation of Igneous Rocks A. Intrusive Rocks- form from magma that cools belowthe surface of the earth. Ex. Granite B. Extrusive Rocks-form as lava cools on the surface of the earth. Ex. Obsidian
Granite Examples: Formation of Igneous Rock • -Extrusive-Formed from lava; volcanic • Intrusive- Formed deep within the earth Obsidian Pumice
Textures of Igneous Rock 1. Glassy 3. Fine-grained 2. Coarse-grained Obsidian Granite Basalt
2. Metamorphic Rocks • Formed from heatandpressure changing the original or parent rock into a completely new rock. The parent rock can be either sedimentary, igneous, or even another metamorphic rock. 1. Schist 2. Marble 3. Slate
Classifying Metamorphic Rocks 1. Foliated-when mineral grains flatten and line up in parallel layers. 2. Unfoliated-when mineral grains grow and rearrange but do not form layers.
Foliated Gneiss
Unfoliated Marble
3. Sedimentary Rocks • Form when sediments are pressed and cemented together, or when minerals form from solutions. • Usually consist of layers 1. Siltsone 3. Shale 2. Conglomerate
Classification of Sedimentary Rocks 1.Detrital Sed. Rocks- (Clastic Rocks)- Made of the broken fragments of other rocks. A.Weathering- the process of breaking rocks into smaller pieces. Happens when rock is exposed to air, water, or ice. B.Erosion- the movement of weathered material.
C.Compaction- when the sediments stick together and form solid rock. D.Cementation- when large sediments are held together by natural cements that are produced when water soaks through rock and soil. E.Shape & Size- 1. Conglomerate- when the sediments are rounded 2.Breccia- when the sediments have sharp angles.
Clastic Rocks • 2. Mudstone • Conglomerate • 1. Sandstone
2.Chemical Sed. Rocks- Formed when dissolved material comes out of solution by inorganicprocesses such as evaporation. Examples are 1. Limestone and 2. Rock Salt
3.Organic Sedimentary Rocks- Rocks made from the remains of once-living things Coquina
Organic Sed. Rock Examples 1. Chalk 2. Coal
Fact about the Mississippi River Did You Know? • The Mississippi River carries an average of 436,000 tons of sediment each day • It moves an average of 159,000,000 tons of sediment a year