Geologic Classification of Aquifers

Abstract

ABSTRACTThis classification of aquifers is based upon the properties of rocks which affect ground water. In any region the rocks may be consolidated or unconsolidated. They may be uniform in lithology, or they may consist of alternating layers of different lithologies. They may have been tilted, fractured, or altered in various ways since their formation.Consequently the occurrence of ground water depends not only on the fundamental nature of the rocks but also on their geologic history. The ground water may be found under confined (artesian) or unconfined (water table) conditions. The permeability of an aquifer may be uniform, or it may vary in some regular way, or it may be very irregular because most of the water is in secondary openings.As most geologic situations do not fit well into precise categories, some aquifers may fall into more than one subdivision of this classification.