Cryogenic Mineral Formation in Caves

Glaciochemistry of Cave Ice: Paradana and Snežna Caves, Slovenia

“…An alternate interpretation is that in the winter, as these drip-water ponds freeze, CaCO 3 precipitates due to the lower pCO 2 concentrations in the cave air as observed by Huang et al [27] in caves in Italy. Calcium carbonate minerals could also form by freezing of drip pond water, thereby concentrating solutes in the remaining liquid until precipitation occurs [28]. Although we cannot rule out these mechanisms a priori, it would seem that in the case of these ice deposits, the precipitated CaCO 3 would be preserved in the ice as particulate material.…”

Cryomorphological Topographies in the Study of Ice Caves

“…In these caves, the mean temperatures below 0 • C for more than two consecutive years lead to consider this type of cavities as periglacial representation of sporadic permafrost (already understood as such by several researchers [19][20][21] and recently noted in Picos de Europa [22,23]; and based, particularly in the last five years, on cryogenic cave carbonates as an important dating tool [24][25][26][27][28][29][30][31][32], some of them focussed on Pyrennean ice caves [33]) and even seen as a specific type of permafrost: endokarstic permafrost high mountain environment as has been considered for the Picos de Europa caves [34,35]. They are thus considered for Spanish ice caves included in endokarstic periglacial phenomena when there are at least perennial ice block, as they fulfill the thermal parameters that defines them [36], confirming the existence of permafrost high mountain environment in the calcareous mountains of the north of the Iberian Peninsula.…”

Winter Wonderland Cave, Utah, USA: A Natural Laboratory for the Study of Cryogenic Cave Carbonate and Thawing Permafrost

“…A unique proxy demonstrated to provide information about past episodes of permafrost thaw, a transition that is often particularly disruptive to landscapes, ecosystems and infrastructure, is cryogenic cave carbonate (CCC). These minerals form when liquid water enters a cave containing subzero temperature conditions 13 . As this water freezes, solutes are concentrated in the remaining liquid until saturation is reached and precipitation of CCC is induced 14,15 .…”

“…The large surface area of this thin layer facilitates degassing of CO 2 , preferentially removing 12 C, and leaving the remaining water enriched in 13 C through kinetic effects 19,20 . Simultaneously, the preferential incorporation of 18 O in the ice is counterbalanced by evaporation of lighter H 2 16 O from the water surface, yielding a characteristically enriched δ 13 C and relatively unaltered δ 18 O signature 18 . The ice involved in the formation of CCC ne does not need to be perennial, however the presence of CCC ne in a currently ice-free cave is nonetheless clear evidence for colder conditions in the past.…”

“…Because the temperature in the main part of the cave (below the permafrost table) is still subzero, these pools freeze over, creating (semi)closed-system conditions in which degassing of CO 2 and evaporation of water are greatly reduced 21 . Slow freezing of these isolated volumes of water precipitates CCC coarse distinguished by less enriched δ 13 C and notably depleted values of δ 18 O compared with CCC ne 13,15,23 . As is apparent throughout Arctic and high mountain environments today, elevation of ground temperature above 0°C, thawing of permafrost, and melting of ground ice are step-changes with dramatic repercussions for landscape and environmental evolution 24 .…”