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Earth Science Ch. 6
Chapter 6
| Term | Definition |
|---|---|
| sediment | small pieces of rock that are moved and deposited by water, wind, glaciers, and gravity. |
| lithification | the physical and chemical processes that transform sediments into sedimentary rocks. |
| cementation | process of sedimentary rock formation that occurs when dissolved minerals precipitate out of groundwater and either a new mineral grows between the sediment grains or the same mineral grows between and over the grains. |
| bedding | horizontal layering in sedimentary rock that can range from a few millimeters to several meters thick. |
| graded bedding | type of bedding in which particles sizes become progressively heavier and coarser toward the bottom layers. |
| cross-bedding | depositional feature of sedimentary rock that forms as inclined layers of sediment are carried forward across a horizontal surface. |
| clastic sedimentary rock | most common type of sedimentary rock, formed from the abundant deposits of loose sediments that accumulate on Earth's surface; classified according to the size of their particles. |
| clastic | rock and mineral fragments produced by weathering and erosion and classified according to particle size and shape. |
| porosity | percentage of open spaces between grains in a material. |
| evaporite | the layers of chemical sedimentary rocks that form when concentrations of dissolved minerals in a body of water reach saturation due to the evaporation of water; crystal grains precipitate out of solution and settle to bottom. |
| foliated | metamorphic rock, such as schist or gneiss whose minerals are squeezed under high pressure and arranged in wavy layers and bands. |
| nonfoliated | metamorphic rocks like quartzite and marble, composed mainly of minerals that form with blocky crystal shapes. |
| regional metamorphism | process that affects large areas of Earth's crust, producing belts classified as low, medium, or high grade, depending on pressure on the rocks, temperature, and depth below the surface. |
| contact metamorphism | local effect that occurs when molten rock meets solid rock. |
| hydrothermal metamorphism | occurs when very hot water reacts with rock, altering its mineralogy and chemistry. |
| rock cycle | continuous, dynamic set of processes by which rocks are changed into other types of rock. |