by Buford » Dec 25, 2011 11:11 am
Al Krause and I, upon examining them, concluded they are not the snottites described in the scientific literature. Our examples have droplets on thin strings, and the droplets are capped by fine dendritic webs, whereas snottites are strings, strands, sheets, and webs of mucous-like material. That being said, I'll admit that I don't know what they ARE, and that they could indeed be another form of whatever composes snottites that is previously undescribed. Yes, that would indeed be interesting.
The Floridan Aquifer is a lens of freshwater lying atop mineralized waters. The latter are brines, formerly sea waters, as the Floridan Plateau was formed under shallow seas. Given its history, the depth of the brines, and their distance from the oxygenating atmosphere, it is not uncommon for sulphur to accumulate down there as H2S gas. Not infrequently, fractures allow small amounts of deep brines to rise into phreatic caves. I have seen small, imperceptibly-flowing brine seeps in a few underwater caves (Cold Sink cave and the Telford-Luraville Cave system, for example). They can be recognized by their colors, usually pale blue (methanogenic? magnesiogenic?) and yellow-brown (sulphurous?). Because they occur at the interface between sedimented floors and cave walls, they can also be recognized by the presence of thin grooves etched into the cave walls by sulphuric acid, tracing lines from the seeps upward toward the cave ceiling. Furthermore, in stagnant conditions, pale turquoise-blue water from the seep can pool up in small, shallow depressions around seep vents. (Interestingly, tiny crustaceans, possibly ostracods or copepods, feed immediately above these pools – I have tried to capture them with a slurp gun, but they are FAST and I couldn’t get the gun barrel anywhere near them).
This is not relatable to the current situation. The examples I am reporting are high on the walls and ceilings in caves having high air exchange fluxes, so presumably any acidic gases injected into the cave atmosphere would quickly be diluted and carried away. Also, there are no wall grooves leading to or away from them, instead they occur in relatively wide, horizontal bands.
North Peninsular Florida is subtropical and averages 54 inches of rainfall annually. The forest above is semi-evergreen and lush, with a detrital layer of leaves, twigs, etc appx 2 – 4 inches thick. Roots from the forest find numerous routes (fractures, solution pipes, and cave entrances) through the thin (< 10 ft thick) overlying bedrock. The cave where the pics were taken has abundant roots throughout the grotto where the unknown items occur. When water tables rise, a thin film of organic particulates gets pasted on the walls, along with inorganics and livestock manure leachates. Oh, did I fail to mention the cattle and water buffalo that graze overhead? Also, the cave harbors appx 10 bats each time I visit. These conditions are extremely favorable for fungi. Indeed, macroscopic fungal hyphae are almost everywhere in this cave, including dirt and rock floors, walls, and ceilings, and apparently on the suspect droplets. Thus, I am convinced they are bio-formations and are either fungal or a combination of bacterial and fungal.
But I could be wrong, and often am. The litmus paper should arrive, and I’ll be returning to finish the survey of that cave, by the middle of the coming week. Alan will also be here to obtain better photography of these materials. Stay tuned!