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The Karst Page

The first three tabs below outline the general aspects of karst features for those who may be new to caving, and includes quite a few examples and diagrams, from both here in the hills and elsewhere. The next two tabs go on to surmise my current thoughts on Black Hills area caves and their speleogenesis while the last tab deals with the geochemical aspects of cave formation. There is a lot more science and opinion in the last three tabs, but that’s a natural consequence of my background, many years of observations and the countless discussions I’ve shared with so many like-minded and observant souls.

No apologizes for the opinions, as I hold that I come by them honestly. We should each openly embrace the freedom to question and challenge…that’s what science, learning and the pursuit of knowledge are all about.
Keep pushing the envelope or you’ll never get out of the bubble of complacency.

KME

“Consider your origin. You were not formed to live like brutes but to follow virtue and knowledge.”
― Dante Alighieri, The Divine Comedy

What is Karst?

Karst Definition

Karst is a distinctive type of topography and morphology formed from the dissolution of soluble rocks such as limestone, dolomite and gypsum. Karst areas are typically characterized by underground drainage systems with sinkholes, dolines and blind valleys on the surface and by caves, solution cavities and solution enlarged fracture systems in the subsurface.

karst-diagram_5
  • Karst features can develop both above and below the water table and they are typically classified based on that distinction.
  • The karst features that develop below the water table are referred to as having a “phreatic” origin and those that take place above the water table are due to”vadose” processes.
  • Phreatic passages are wider than they are tall. They tend to meander and have rounded or flattened ovoid profiles as shown in the adjaent diagram. Phreatic passageways are typically found developed along bedding planes.
  • Vadose passages and developments tend to be linear, and follow fracture systems or to be modifications of earlier phreatic features, In general, vadose developments tend to be taller than they are wide and often have a canyon-like notch at the base of the passage.
  • Since vadose modifications often account for the later-stage decorative formations overprinted on earlier phreatic features, vadose developments are sometimes referred to as “secondary” and the phreatic type as “primary”.
  • Karstic and cave systems can develop almost entirely from one or the other of these two end-member processes, but most have origins due to recognizable contributions from both. The adjacent diagram shows a phreatic passage that has been modified by a vadose notch or “canyon” at the base.
  • There are many terms used in various parts of the world for karst related features. The usages are sometime overlapping, and can be confusing depending on the areas they describe. For a more complete listing and decoding of karst terms, it is helpful to refer to one of the the following sources: