The aquifer is regarded as the infinite water body, so the boundary between the aquifer and the
aquitard can be treated as the constant pressure boundary.
Both superimposed and partially disjointed aquifer assemblages are separated by
aquitards, sealing marlstones, leading to substantial differences in their groundwater chemistry.
A professor of geology in the department of geological sciences, Hendry said that despite the importance of
aquitards, "they are among the most difficult geological features to study and thus the least-understood area in groundwater science."
The Middle Aquifer, where present, is confined by the upper
aquitard, a clay-silt layer.
Aquitards have very slow permeability whereas aquicludes are essentially impermeable.
The designation of a stratum as an aquifer or
aquitard is relative to its neighboring strata.
These aquifer systems are separated by the Lukati-Lontova
aquitard ([[??].sub.1]Lk-[[??].sub.1]Ln).
Ground water tends to flow through aquifers constrained by layers of less-permeable rock called
aquitards. Hydrologists believe a ground water's age reflects the time it takes to migrate along the aquifer.
The [D.sub.3]jr layer can be considered as a regional
aquitard which essentially complicates vertical groundwater exchange between the underlying terrigenous Midddle-Upper Devonian aquifer ([D.sub.3-2]sv-up).
The Second Canadian Symposium on
Aquitard Hydrogeology was held this past June at the University of Ottawa, Ontario, and brought together over 120 geoscientists from Hong Kong to Bern and from Mississippi to Saskatoon.
Weaver TR, Cherry JA, Frape SK (1996) Hydrodynamic response of a clay-till
aquitard to changing potentiometric conditions in an underlying water-supply aquifer: implications for solute and contaminant transport.