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ES - Ch 4 - Rocks
Rocks
Question | Answer |
---|---|
Rock | Mixture of one or more minerals, rock fragments, volcanic gases, organic matter, or other natural materials; can be igneous, metamorphic, or sedimentary. |
Rock Cycle | Model that describes how rocks slowly change from one form to another through time. |
Igneous Rock | Rock formed when magma or lava cools and hardens |
Lava | Molten rock that flows from volcanoes onto Earth's surface. |
Intrusive | Describes a type of igneous rock that generally contains large crystals and forms when magma cools slowly beneath Earth's surface. |
Extrusive | Describes fine-grained igneous rock that forms when magma cools quickly at or near Earth's surface. |
Basaltic | Describes dense, dark-colored igneous rock formed from magma rich in magnesium and iron and poor in silica. |
Granitic | Describes generally light-colored, silica-rich igneous rock that is less dense than basaltic rock. |
Metamorphic Rock | Forms when heat, pressure, or fluids act on igneous, sedimentary, or other metamorphic rock to change its form or composition, or both. |
Foliated | Describes metamorphic rock, such as slate and gneiss, whose mineral grains line up in parallel layers. |
Nonfoliated | Describes metamorphic rock, such as quartzite or marble, whose mineral grains grow and rearrange but generally do not form layers. |
Sediment | Loose materials, such as rock fragments, mineral grains, and the remains of once-livign plants and animals, that have been moved by wind, water, ice or gravity. |
Sedimentary Rock | Forms when sediments are compacted and cemented together or when minerals form from solutions. |
Compaction | Process that forms sedimentary rocks when layers of sediments are compressed by the weight of the layers above them. |
Cementation | Sedimentary rock-forming process in which sediment grains are held together by natural cements that are produced when water moves through rock and soil. |