Tubular Lava Helictites

Helictites are an eccentric or “vermiform” form of stalactite that twists and turns rather than growing straight up and down. They typically begin as tubular lava stalactites, but crystallization of the emerging lava as it cools pushes the lava in different directions. Often groups of these helictites will bend in the same direction down the passage, as in photo 4, suggesting an influence of wind moving through the tube.

Helictites rarely have drip stalagmites lying underneath. Most likely, the crystallization at the ends of the tubes that redirect the flow also reduces it to the point that little material is ejected to fall on the floor beneath.

The first photo shows a group of small helictites on a ceiling with some possible tube slime. In the second and third photos, some unusually long (over a foot) helictites formed on the end of some tubular lava stalactites. The fourth photo shows ta directionality possibly reflecting air currents during their creation.

Needless to say, these formations are extremely delicate and caution must be taken when exploring near them.

AUTHOR: Dave Bunnell