Models of Karst Development from the Initial State to Maturity

Abstract

The evolution of secondary permeability in soluble rocks is determined by two fundamental factors. The first is the field of hydraulic gradients within the primary voids and partings of the rock which establishes flow of aggressive water from points of input to points of output. The second factor is the kinetics of the dissolution reactions. These determine to which extent the earliest initial flow paths are enlarged by dissolution. If saturation, with respect to calcite, is attained very quickly, dissolution can be active only at very short distances from the input, and only insignificant changes of the first flow channels result. On the other hand, at slow approach to equilibrium the earliest flow channels are modified by dissolution along their entire length. This changes the distribution of the pressure field and accordingly changes the flow fields. It is the purpose of this chapter to describe the evolution of karst according to these mutually interrelated factors.