- 1. Those parts of the earth’s crust in which all voids are filled with water under pressure greater than atmospheric .2. That part of the earth’s crust beneath the regional water table in which all voids, large and small, are ideally filled with water under pressure greater than atmospheric . When discussing a karst setting, it is preferable to use the term, phreatic zone, so as to avoid confusion regarding chemical saturation.Synonym: saturated zone.See also zone of saturation.
A Lexicon of Cave and Karst Terminology with Special Reference to Environmental Karst Hydrology. Courtesy of the author & The Karst Waters Institute. 2002.
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Phreatic zone — The phreatic zone (from Ancient Greek phrear, phreat a well ), or zone of saturation, is the area in an aquifer, below the water table, in which relatively all pores and fractures are saturated with water. The phreatic zone may fluctuate with… … Wikipedia
Phreatic — The term phreatic is used in Earth sciences to refer to matters relating to ground water below the static water table (the word originates from the Greek phrear , phreat meaning well or spring ). The term phreatic surface is where the hydrostatic … Wikipedia
phreatic cave — 1. Cave conceived and developed by dissolution, usually below the water table, where all voids are water filled within the phreas. Phreatic caves may include loops deep below the water table, particularly in dipping limestone with widely… … Lexicon of Cave and Karst Terminology
phreatic water — That part of the underground water in a karst limestone which lies within the zone of permanently saturated rock the phreatic zone. Caves formed within this zone are known as phreatic caves . See phreas … Lexicon of Cave and Karst Terminology
zone of saturation — The zone in permeable soil or rock that is saturated with water; the phreatic zone . See also phreatic zone … Lexicon of Cave and Karst Terminology
phreatic surface — water table (top of the zone of saturation) … Dictionary of ichthyology
phreatic — [frɪ atɪk] adjective Geology relating to or denoting underground water in the zone below the water table. Compare with vadose. ↘(of a volcanic eruption) caused by the heating and expansion of groundwater. Origin C19: from Gk phrear, phreat a well … English new terms dictionary
phreatic — adj. Geol. 1 (of water) situated underground in the zone of saturation; ground water. 2 (of a volcanic eruption or explosion) caused by the heating and expansion of underground water. Etymology: Gk phrear phreatos well … Useful english dictionary
Vadose zone — [ capillary fringe, water table, and phreatic or saturated zone. (Source: United States Geological Survey.) ] The vadose zone, also termed the unsaturated zone, is the portion of Earth between the land surface and the phreatic zone or zone of… … Wikipedia
transition zone — 1. Portion of bedrock in the vadose zone that is between the epikarst zone and the phreatic zone, is relatively waterless and unfractured, but is locally breached by discrete percolation points (vadose shafts.) 2. The zone in which the… … Lexicon of Cave and Karst Terminology