Rafts are thin, sheet-like deposits that form on cave pools. They form when mineral-laden dripwater hits a pool surface, spreading out and depositing its mineral content as a thin crust. The top image shows very thin films of calcite floating on a pool. As these thicken, they often sink to the bottom. The middle image shows a large raft in a now-dry pool basin. In some cases, rafts may also "glue" themsleves to the side of the pool edge, as seen in the bottom photo. This photo shows the edge of a large, now-dry pool basin, which had been stained orange from iron impurities in the calcite. In Lechuguilla Cave, New Mexico, deposits of rafts several feet thick are found in old pool basins. Sometimes these pile up and form raft cone stalagmites

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	Created: December, 1998 Updated May 4, 2005 Author: Dave Bunnell