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Abstract:
The authors de scribe a 7 km long phreatic maze they discovered and explored during the last decade of the 2Oth century in South Africa, developed in the late Archean dolostone in the Malmani Subgroup. This cave is of interest mainly for two aspects. Firstly the cave intersects paleokarst channels filled with bleached kaolinic residuals of Permian age. This paleokarst is most likely to have developed relatively shortly after the Gondwana glaciation in a cool, humid climate. Secondly the cave is remarkable by the abundance of aragonite speleothems. Particularly interesting are subaquatic aragonite formations: rafts, cones, volcanoes, sea urchins and pool floor crust. Aragonite rafts are always associated with more or less calcite, which seems to have formed first and was apparently essential in the initial formation of this speleothem. In the pool floor crust, a cyclical calcite-aragonite deposition seems to correspond to alternation of humid and dry periods, calcite representing wet years. The amplitude of this cycle is possibly in the order of a few decades. Phosphate minerals which developed on cave soil, rock and carbonate speleothems in contact with bat guano, have been identified, in particular the rare mineral collinsite