Spelunking Challenge: Speleogens vs Speleothems

You probably remember stalactites and stalagmites from school – (remember “c” for “ceiling,” and “g” for “ground).

But let’s try exploring another important caving duo – speleogens and speleothems!

Rather than noting their position within a cave, these two caving opposites refer to the process through which a cave feature was formed.

Speleogens are relief structures, meaning they created through a process of erosion of surrounding materials. Imagine the way a sculpture is created by chipping away at a block of marble. Speleogens are similar!

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Image by Zoe Gilette

Speleogens

  • Anastomoses are channels carved away by water flow through the stone. Sometimes these can look similar to stalactites, though they were created by carving around the rock rather than adding new minerals.
  • Another speleogen structure is the scallop, a spoon-like scoop into the rock also caused by water flow. Scallops can give information about the water’s direction and velocity as it passed through the cave.
  • Boxwork is one of the prettiest types of speleogen, created by minerals accumulating in cracks between stones. The stone can then erode over time, leaving just the honeycomb shape of the boxwork in relief.

Speleotherms

  • Stalactites and stalagmites fall under this category. These structures are formed by water dripping from the ceiling and leaving an accumulation of minerals behind over time, which build columns that protrude from both the ceiling and floor.
  • Helictites are contorted speleothems that twist in many directions, rather than just forming vertically. These can be very beautiful, and seem to defy of gravity!
  • Flowstone is created from water rich in calcium carbonate flowing along the cave floor. Flowstone often resembles a petrified waterfall or layer of cake icing.
  • Draperies are like a sheet of stalactite rather than just one cone or column. They look just like their namesake! They are also sometimes called “cave bacon” when you can see clear distinctions between their layers.

Whether you’re feeling more speleogenic or speleothermic today, pick your team and let the competition begin!

The competition starts at 11:00 AM ET on 3/31 and goes for 48 hours. Bonus information is detailed in your notifications.

Featured Art by Daniela Gamba