THE SCIENCE OF CAVES AND KARST: A HALF-CENTURY OF ADVANCES
The first borrowing was the restructuring of carbonate chemistry to define saturation index, CO2 partial pressure and other parameters which are widely used to describe karst waters. Equilibrium chemistry was followed by chemical kinetics which proved to be the key to understanding the development of conduit systems. Karst hydrology advanced by recognizing the importance of the karst drainage basin with surface water-ground water interactions and the hydrodynamics of conduit flow. Much new interpretation was made possible with data provided by greatly improved tracer techniques. Karst hydrology has moved from qualitative descriptions to computer models that take account of matrix, fracture, and conduit permeability. Sediment and contaminant transport as well as new understanding of sinkhole collapses and other land use hazards have become part of the hydrogeologic framework of karst.
A second borrowing was the rapid development of age dating techniques. Advances in Uranium/thorium dating allowed construction of complete growth profiles for stalagmites. Argon-argon and uranium-lead dating extended the time scale to millions of years. Paleomagnetic dating and cosmogenic isotope dating of clastic sediments, if not dating the cave passages themselves, at least date the time at which the cave was part of the active drainage system. Dated master trunks become important time markers for landscape evolution. There is also an enlarged vision of karst processes with recognition of hypogene karst, eogenetic karst and others.
Speleothems are now recognized as an important paleoclimate archive for continental interiors. Accurate age dating along with the measurement of oxygen, carbon, and hydrogen isotope profiles, trace element profiles, and crystal growth characteristics give much insight into changing climates well back into the Pleistocene. Records of even deeper time are sitting in caves awaiting the development of suitable techniques for reading them.