Geology relative dating activity
astrobleme - A circular erosional feature that has been ascribed to the impact of a meteorite or comet.atmosphere (unit) - A unit of pressure equal to 101,325 newtons per square meter, or about 14.7 pounds per square inch.atoll - A continuous or broken circle of coral reef and low coral islands surrounding a central lagoon.autochthonous - Refers to something formed in its present location. backwash - The return flow of water down a beach after a wave has broken.amber - A fossilized resin from a coniferous tree that sometimes contains entrapped and preserved insects.amphibole - group of generally dark-colored rock-forming inosilicate minerals, composed of double chain Si O), less mafic than basalt, but more mafic than dacite; rough volcanic equivalent of diorite.
angstrom - A length of 10 meter or one hundred millionth of a centimeter. angular unconformity - An unconformity in which the bedding planes of the rocks above and below are not parallel.Thus water in the well rises above the surrounding water table.asphalt - A dark bituminous substance found in natural beds. asthenosphere - The highly viscous, mechanically weak region of the upper mantle of the Earth that lies below the lithosphere at depths between 100 and 200 km below the surface.bar (stream) - An accumulation of sediment, usually sandy, which forms at the borders or in the channels of streams or offshore from a beach.
barchan - A crescent-shaped sand dune moving across a clean surface with its convex face upwind and its concave slip face downwind.anthracite - The most highly metamorphosed form of coal, containing 92 to 98 percent of fixed carbon. anticline - A fold of rock layers with a convex shape pointing upwards. aphanitic - An igneous rock in which the matrix grains are too small to be seen with the unaided eye. aquifer - A permeable formation that stores and transmits groundwater in sufficient quantity to supply wells.