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Published byDarcy Hopkins Modified over 9 years ago
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Igneous Rock...
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Two types of molten rock: Igneous Rocks Felsic Mafic High in silicates Low in silicates slow flowing light color fast flowing dark color Molten Rock: Rocks made:
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Igneous Rocks Felsic Mafic Granite Hornblende
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Above the surface − Extrusive or volcanic. − Cools and solidifies quickly. − Crystals with small grain size or no crystals at all (glass). − Can also show air gaps from bubbles. Relatively light. Igneous Rocks Form in 2 places:
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Igneous Rocks Below the surface − Called intrusive or plutonic. − Cools and solidifies slowly. − Shows crystals with large grain size.
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Volcanic Rock Plutonic Rock
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Igneous Rocks Descriptive Terminology of Rock Texture Texture: the size, shape, and arrangement of the mineral crystals in the rock. Porphyry: Large crystals are surrounded by a fine-grained mass of rock. It can also have bubbles. Frothy: Rocks with no crystals/minerals visible. Has many air gaps (bubbles) and has a foamy appearance.
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Igneous Rocks Descriptive Terminology of Rock Texture Fine Grain: Small, barely visible crystals. Seen with the aid of a magnifying glass. Coarse Grain: Large crystals, visible with the un-aided eye, of various minerals in the rock together. Glassy: Rocks with no crystals and a clear or translucent appearance.
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FrothyPorphyry Coarse GrainFine Grain
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Obsidian (Black Volcanic Glass) Pumice (Frothy and porous) Scoria (Frothy and porous)
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