159-8 Volcanic Karst Systems

Session: Hypogene Speleogenesis: An Overview of Research in Memory of Dr. Alexander Klimchouk

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Several geologic conditions, including shallow igneous activity, facilitate hypogenic karstification in which the acids dissolving the carbonate rocks are generated at depth. Hydrothermal, deep-seated karst is documented, but the mechanisms are not commonly applied in geologic evaluations. Shallow magmatic and volcanic activity provide conditions that can rapidly dissolve large voids deep below the Earth's surface. Volcanogenic karstification has produced some the Earth's deepest underwater cave systems. Volcanogenic karst systems (VKS) in Mexico, Australia, Turkey, Czech Republic, Italy, and perhaps Texas reveal certain commonalities. Volcanogenic karstification needs on four components to initiate and develop deep, subsurface voids: 1) thick carbonate strata, 2) preferential groundwater flow paths (fractures), 3) volcanic/igneous activity that releases acids, and 4) flux of groundwater through the system. The order of occurrence (from 1 to 4) is critical to develop VKS. Components 1, 2, and 4 are common to most karst, but component 3 can accelerate dissolution processes. High fluxes of carbonic, sulfuric, and other acids can create hyper-aggressive subsurface conditions that rapidly dissolve carbonate rocks.  Compared to adjacent epigenetic karst, VKS may be somewhat isolated from surrounding epigenetic karst both physically and chemically; have different speleothems and water chemistries; and, when actively forming, have higher temperatures.  With time, these systems may acquire an epigene overprint. Volcanogenic karstification can produce deep solution porosity and high permeability where older carbonate rocks are associated with younger volcanic/magmatic systems; we hypothesize that there are undiscovered VKS now developing at depth.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-4851

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