Cyanobacterially deposited speleothems: Subaerial stromatolites

Caves in caves: evolution of post-depositional macroholes in stalagmites

“…Cox et al, 1989;Cunningham et al, 1995;Jones, 2011). Conversely, bacterial activity is also an important factor in controlling bio-erosion in caves (Viles, 1984;Northup and Lavoie, 2001;Naylor et al, 2002;Cockell and Herrera, 2008).…”

Algae promote growth of stalagmites and stalactites in karst caves (Škocjanske Jame, Slovenia)

“…In sunilluminated cave entrances other formations of carbonate depositions can also be found. Their growth is somehow linked with biolithogenic activity of certain organisms: tufaceous deposits associated with moss Eucladium verticillatum (Dalby 1966), a colony of alga Gleocystis rupestris in the form of a stalactite (Cubbon 1976) and stromatolitic stalagmites known as subaerial stromatolites (Cox, James, Leggett and Armstrong 1989;James, Patsalides and Cox 1994) are the best known examples. Accumulation of carbonate sediment in the form of subaerial stromatolites resembles Precambrian and Phanerozoic stromatolites; i.e.…”

“…It is assumed that morphology and growth of subaerial stromatolites depends notably on the angle of incoming light and thus on the speed of cyanobacterial growth. Cox, James, Leggett and Armstrong (1989) identified on the stromatolites' surface coccid cyanobacteria Gloeocapsa sp., while in the distinctive inner layers no structures resembling cells were observed (James, Patsalides and Cox 1994 these stalagmites fatty acids profiles, n-alkanes, N/C ratio, portion of free and bound amino acids indicate biological origin of the structure (James, Patsalides and Cox 1994). CaC0 3 precipitates in the form of stromatolitic stalagmites due to changed equilibrium of partial pressure of CO 2 in dripping water relative to the partial pressure of CO 2 in the cave atmosphere, higher temperatures in the eave entrance which reduce the rate of dissolved CO 2 in dripping water and thus enhance precipitation of CaCO" and finally due to photosynthetic organisms which lower -partial pressure of CO 2 in dripping water (Cox, James, Leggett and Armstrong 1989).…”

Biomineralization and phytokarst development on cavernous Quaternary carbonate terraces, Mohammedia, northwest Morocco

“…Most studies in the vadose diagenetic environment have concentrated on the transformations that take place in the main body ofthe vadose zone and only a few studies have focussed on the role of bacteria in the formation of authigenic cave minerals (Gomes 1985;Cox et al 1989). Few have demonstrated a sequence ofmineral growth that can be used in cementation models relating early to late cements in caves (Leveille et al 2000;Hose et al 2000;Cox et al 1989;Jones 1989 andKahle 1986).…”

“…Few have demonstrated a sequence ofmineral growth that can be used in cementation models relating early to late cements in caves (Leveille et al 2000;Hose et al 2000;Cox et al 1989;Jones 1989 andKahle 1986). In the example studied here, colonizers invade cavities and other sedimentary structures on terraces of coastal Morocco and replace existing carbonates through processes leading to the formation of cavernous stromatolites.…”