A KARST-PSEUDOKARST MORPHOGENETIC SPECTRUM BASED ON FORM, PROCESS, AND STAGE

Pseudokarst is generally regarded as a landscape where morphological features resemble true karst but lack the element of long-term evolution by dissolution of rock. Pseudokarst may or may not have a preponderance of subsurface drainage through conduit-type voids. Morphologies of pseudokarst may be rheogenic (formed in lava), littoral (eroded by waves), tectonic or gravitational (accumulation of talus, block and debris movements), ablational (wind action on rock or ice), suffosional (groundwater piping), corrasional (water carved), thermal (created by hydrothermal or permafrost activity), or biogenic (significant contribution of organic processes). Some notable examples include lava tubes, sea caves, boulder caves, rock cities, glacial caves, aeolian caves, badland caves, rock shelters, crevice caves, various forms of sinkholes in these settings, and even casts of organisms.

In many cases, morphologies of pseudokarst are transitional, among themselves or with morphologies of true karst. As a result, a classification scheme has been formulated that arranges morphologies in a suite of gradational representations. A simple arrangement positions landforms along a linear spectrum from true karst (100% dissolutional in origin) to definitively pseudokarst (0% dissolutional), with intermediate positions as the case may be. Alternatively, ternary and pyramidal diagrams position pseudokarst subtypes according to the corrasional role of fluids (water, ice, and air), degree of physical weathering (disaggregation), and transport (gravitational processes, fluid transport). Composition and structure of host materials add additional dimensionality to the graphical spectral schemes. In this manner, pseudokarstic landforms may be conveniently arranged in a three-dimensional continuum for ease in classification and interpretation.