Very commonly, lava tubes are floored with a rough, bumpy, frothy surface that is transitional between a smooth, ropy pahoehoe  lava (common on tube floors) and pure aa lava (which is unusual on tube floors).  It may include chunks of breakdown and broken pieces of stalactites.  The cauliflower form is a solid floor, whereas floors with loose fragments of rough lava (as opposed to breakdown) are called clinker floors.

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	Created: August 4, 2000 Author: Dave Bunnell