Difference between radiometric carbon dating top ten world dating sites
atoll - A continuous or broken circle of coral reef and low coral islands surrounding a central lagoon.
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.
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.
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.