Inside EarthChapter 5 Rocks

5.2 Igneous Rocks

5.2 Igneous RocksLEARNING TARGETS

• I can identify characteristics that are used to classify igneous rocks.

• I can understand how are igneous rocks used.

classify igneous rocksI can identify characteristics that are used to classify igneous rocks.

Three ways to classify Igneous Rocks1. Origin – Intrusive / Extrusive2. Texture – Course grained to Fine grained3. Mineral Composition

5.2 Igneous RocksKey Terms

Extrusive – Igneous rock that forms from lava above the Earth’s surface.

5.2 Igneous RocksKey Terms

Intrusive – Igneous rock that forms when magma hardens beneath Earth’s surface.

5.2 Classifying Igneous Rocks

Origin – Form beneath the surface INTRUSIVE (Slow cooling)Form on the surface EXTRUSIVE (Rapid cooling)

Texture – Fine grain cool RAPIDLY Coarse grain cool SLOWLY

Mineral Composition – The mineral content of magma variesLight color generally high silicaDark color generally low silica

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