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Gen. Science Mod. 6
Foundations of Geology
Term | Definition |
---|---|
catastrophism | the view that most of earth's geological features are the result of large-scale catastrophes such as floods, volcanic eruptions, etc. |
uniformitarianism | the view that most of earth's geological features are the result of slow, gradual processes that have been at work for millions or even billions of years |
humus | the decayed remains of once-living creatures |
sedimentary | rock that is formed from sediments which are laid down by water or some other agent and fuse together due to heat, pressure, and various chemical reactions |
sediments | sand, silt, and other components of soil |
igneous | rock that forms from molten rock (magma, lava from volcanoes) |
metamorphic | rock that has undergone extreme change due to lots of heat and pressure |
minerals | inorganic crystalline substances found naturally in the earth |
inorganic | did not come from a living being |
crystalline | having a very sharp, geometric shape |
strata | layers |
lamination | a single layer of rock that is less than 1 centimeter (0.39 inches) thick |
laminae | several lamination layers formed right next to each other |
weathering | the process by which rocks are broken down by the forces of nature |
erosion | the process by which sediments and rock fragments are carried away by wind or rain |
groundwater | water that flows underground |
cavern | open space underground where groundwater has eroded the rock |
stalactite | an icicle-like structure hanging down from the ceiling of a cavern formed by groundwater dripping and leaving sediment on the ceiling |
stalagmite | a structure rising from the ground of a cavern formed by groundwater dripping and leaving sediment on the ground where it dripped |
column | Formed when a stalagmite and stalactite meet |
unconformity | a surface of erosion that separates one layer of rock from another |
angular unconformity | layers below are tilted |
nonconformity | When sedimentary rock rests on top of igneous or metamorphic rock |
disconformity | When strata are parallel |
paraconformity | Uncertain type of disconformity |
intrusion | Veins of igneous rocks shooting through layers of sedimentary rock |
Sills | Veins of rock that run in the same direction as the strata |
Dikes | Veins of rock that run perpendicular to the direction of the strata |