As our caves are quite shallow in many areas, roots very often extend into them in search of water. In areas where you have air spaces entrapped or air domes there is an ongoing calcification process of the roots that from so called rootsicles. As the fossilisation process continues and when the organic material has long since decayed, the calcite deposit preserve their shape and original form, we call these special kind of speleothems rhizomorph. These formation can grow to a considerable length and compared to the growth of stalactites also quicker.
Reference is made to an online Glossary of Caving Terms by Garry K Smith © (Aug.1998) which is very helpful to determine the correct word for some of the formations I get to see on my dives here.
Calcite Rafts are formed when due to the oversaturation of the water with calcite it precipitates and clogs to these small rafts on the surface together. These rafts become after while too heavy to be supported anymore by osmotic tension and sink to the bottom and form a layered sediment deposition. The surfaces has to be protected from wind and stay unmoved for a long period of time so that the wonderful and very easily destroyable rafts can form. Therefore, you never will find them in the entrance areas of the cenotes, however, air domes of cave systems that are not that often dived, have still today surfaces covered with a thick calcite raft layer and in many tunnels you find them as deposition on the floor, which is an indication that for a long period of time this part of the caves was only partially flooded. Formations like these calcite rafts tell the story of the formations of the caves and are as precious and important to save as any other formation in the caves. A lack of current and other disturbing influence have preserved them over hundreds of thousands of years, so the diver should care at all times about a very good buoyancy, distance from the floor and excellent propulsion techniques during the dives.
This story started back in 2009 and I was invited this year to co-author a short article on it that later was published in the NSS (National Speleological Society) News March 2012. I am extremly proud as this is the first big cave diving related publication for me. Thanks to Leigh to have pushed me towards it and to Dave Bunnell for his great website The Virtual Cave and support in finding out how those formations were actually formed.
I can’t claim that I was the first person to dive Cenote Zapote, the cave is not listed in the QRSS cave list of the area, but Vicente Fito’s name is mentioned on an arrow at the line. I did my personal exploration on a day off, with two tanks and a sidemount rig ready and an idea to check out a couple of cenotes whose entrances I had seen some weeks
before. And already a first dive revealed this jewel on September 12, 2009. I immediately realized that this is something special and exactly a month later, I came back with two friends to shoot photos and video. Since that time I have brought numerous people to this special place and it got quite famous among cave divers here, because if you think you have already seen everything, I always can surprise people by showing them this special place.
Continue Reading the Article on Cenote Zapote march 2012 NSS News in English
(from http://en.wikipedia.org/wiki/Stalagmite) are a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. This stalagmite formation occurs only under certain pH conditions within the underground cavern. The corresponding formation on the ceiling of a cave is known as a stalactite. If these formations grow together, the result is known as a column.
As all flowstone formation, this is a secondary stone and at times quite fragile.
The speed of growth is depending on several factors but in general you can say that stalagmites grow slower then their counterparts. Once submerged in the water, these formations do not grow any more and also don’t erode thus are presenting a window into time.
Between two liquids of different densities, always an interface forms in between. Just imagine an oil and vinegar dressing. In the Yucatan aquifer, a similar interface permenantly exists between the fresh and saline waters and is called the halocline (from the APSA Cavern guide manual, section hydrogeology) as this is where there is a strong gradient of change in salt concentration. It is a wonderful experience being able to see and play with the halocline in some cenotes and caves! You can see it with your eyes because some of the beams from your light are refracted, or bounced off the halocline surface. This is also why halocline may look different from above and below as the angle of reflection is different depending whether you are looking from the fresh or saline water into the other.
Cenote Eden for example has a very striking halocline where the thickness is less than 1m, however, much thicker haloclines spanning many metres are common, for example in Mayan Blue’s B tunnel.