21 August 2012
This is a "pendulite"
Cave formations are fascinating. This is one I've never heard of or seen before. It's interesting to ponder the dynamics of how a growing stalactite would transform to have this bulbous tip. Perhaps some alteration in the cave's relative humidity and thus the evaporative rate of the dripping mineralized water?*
From a marvelous collection of photos of caves in Thailand, posted at The Telegraph. After you spot the tiny humans in some of the photos, the scale of the caves becomes stunning.
This image credit John Spies / Barcroft Media.
*Addendum: Reader AM found the explanation (by the photographer): "Pendulites... form when a stalactite reaches a seasonal cave pool. Successive thin layers of calcite build up as the pool dries out each year, creating this odd-shaped formation."