
| Unlike tubular lava stalactites, 
        which are extruded by escaping gases, the shark tooth stalactite grows 
        by accretion. In most cases, as the level of flowing lava inside an active 
        tube fluctuates, it coats protrusions on the ceiling with a thin veneer 
        of lava. The original protrusion may have been a small driplet formed 
        as the molten ceiling cooled. This results in a broad stalactite, usually 
        tapering to a point. A cross section of such a stalactite will show successive 
        layers, just as tube passages contain linings that may be several layers 
        thick from successive flows. In both photos, the stalactites have been encrusted with secondary gypsum deposits. | 
 

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|  | Created: August 4, 2000 Author: Dave Bunnell |