Abstract - Speleogenesis of the Black Hills - Maze Caves - South Dakota - US
Palmer, Arthur N. and Margaret V. 2000. “Speleogenesis of the Black Hills, Maze Caves, South Dakota U.S.”. National Speleological Society. Speleogenesis, Evolution of Karst Aquifers, January 2000 edition. Klimchouk, Ford, Palmer, Dreybrodt editors. 5.2.2., p. 274-281.
Caves of the Black Hills of South Dakota, U.S.A., are located in the Madison Limestone of Mississippian (early Carboniferous) age in a zone of diagenetic breccia and late Mississippian paleokarst. Most of the; caves are extremely complex networks with multiple stratigraphically
controlled tiers. Today they are essentially hydrologic relics. Their history is as complex as the caves themselves:
* The earliest cave openings were formed by diagenetic processes, mainly by the dissolution and reduction of sulfates. Oxidation of hydrogen sulfide produced many small and rather isolated voids lined by brecciated bedrock.
* Late Mississippian exposure produced caves, dolines, and surface fissures, which were later filled with basal Pennsylvanian (late Carboniferous) sand and clay of the Minnelusa Formation.
* Deposition of sedimentary strata buried these early karst features to depths of at least two kilometers. During this time, voids that had not been entirely filled by Pennsylvanian sediment were lined by a thin layer of scalenohedral calcite, and later by quartz.
* Uplift of the Black Hills at the end of the Cretaceous Period and beginning of the Tertiary Period exposed the Madison Limestone once again, allowing rapid groundwater flow through it. The earlier caves and solution pockets were enlarged at this time.
* A thick layer of rhombohedral calcite precipitated on the cave walls, probably as a result of stagnation of groundwater caused by late Tertiary aggradation, which blocked spring openings.
.Both before and after the calcite wall crust was deposited, deep subaerial weathering produced boxwork, with veins of calcite that had replaced earlier sulfates, as well as thick accumulations of carbonate sediment.
The Tertiary cave enlargement probably involved mixing of at least two of the following water sources: artesian flow from recharge along the carbonate outcrop area, diffuse recharge through the overlying sandstone, and rising thermal water. There is evidence for all three sources, but the relative importance of each is still uncertain.