Water containing more than 10,000 parts per million (ppm) of dissolved solids of any type. Brackish water contains between 1,000 and 10,000 ppm of dissolved solids.
A rock fragment or mineral particle smaller than a granule and larger than a coarse silt grain. Its diameter ranges from 1/16 to 2 mm.
Rock or other material that has been worn or broken into small pieces. Sediment is often carried from its original location by wind or water and deposited in other areas.
Rocks formed from sediment, broken rocks, or organic matter. Many sedimentary rocks are formed when wind or water deposits sediment into the layers, which are pressed together by more layers of sediment, forming underground beds of rocks.
Movements in the earth's crust.
A sensor that detects seismic waves generated by earthquakes and cultural activity.
Said of a type of climate in which there is slightly more precipitation (10-20 inches [254-508 mm]) than in an arid climate and in which sparse grasses are the characteristic vegetation.
A rock fragment or mineral particle with a diameter of 1/16 mm to 1/256 mm, smaller than a very fine sand grain and larger than coarse clay.
The interval of geologic time between about 443 million and 419 million years ago.
A mass of soil and rock that moves along a curved failure surface with rotation but without internal deformation of the landslide material.
A place where groundwater flows naturally from the earth into a body of surface water or onto the land surface, at a rate sufficient to form a current.
The finely powdered material left behind when a mineral is rubbed on a piece of unglazed porcelain. This streak may have a different color from that of the mineral itself and is an excellent check in identifying many minerals.
Underground. Below the earth's surface.
Any mining method in which layers of soil, sediment, and rock are removed, or stripped, from the surface to reach and extract underlying rock or mineral deposits, such as coal or zinc.
Water found at the earth's surface, usually in streams or lakes.