The Role of Condensation Corrosion in Thermal Speleogenesis. Study of a Hypogenic Sulfidic cCve in Aix-les-Bains, France

Abstract

UDC 551.435.8:551.3.053(44) Philippe Audra, Fabien Hoblea, Jean-Yves Bigot & Jean-Claude Nobecourt: The role of condensation corrosion in thermal speleogenesis. Study of a hypogenic sulfidic cave in Aixles-Bains, France Condensation-corrosion is an active speleogenetical process in thermal caves where high thermal gradient drives air convection. Wall retreat rates are greater than in meteoric caves. Conversely, evaporation produces depositional processes by replacement of limestone by gypsum and by aerosol decantation leading to the formation of popcorns. The Chevalley Aven belongs to Aix-les-Bains thermal-sulfidic cave system. Condensation occurs at the contact of cool walls of large spheres; conversely, evaporation occurs at the output of the narrow passages where the air sinks down from the upper sphere. A weathered layer and biofilms are present where slow condensation occurs. Corrosion distribution varies according to thermal rock conductivity and causes the sphere to develop upwards, laterally, and divergent. This morphodynamic pattern favors the development of stacked spheres, isolated by narrow necks, and arranged in a bush-like pattern. This development is clearly active in the vadose zone above the thermal water table. We propose that some avens above water table hypogenic caves, like Villa Luz (Mexico), may be of condensation-corrosion origin instead of phreatic. future development will collect physical and chemical data to calculate the condensation-corrosion budget and assess its role in cave development.

Fate of sulfide in the Frasassi cave system and implications for sulfuric acid speleogenesis

“…Rapid H 2 S(g) degassing and subaerial corrosion are expected for most locations within Cueva de Villa Luz, Mexico, due to high H 2 S T and turbulent water flow (Hose et al, 2000), as well as near the highly sulfidic and turbulent cave streams in Grotta Nuova di Rio Garrafo near Acquasanta Terme, Italy (Galdenzi et al, 2010;Jones et al, 2010). Water temperature and thermal air flow may also impact H 2 S(g) dynamics in these and other caves (Galdenzi, 2001;Audra et al, 2007;Audra et al, 2009), and future research will continue to explore how H 2 S T concentration, stream flow characteristics, and other factors impact subaerial sulfuric acid speleogenesis and the evolution of sulfidic karst systems.…”

“…Indeed, the role of subaerial versus subaqueous processes in Carlsbad Cavern currently remains controversial (e.g., Jagnow et al, 2000;Forti et al, 2002;Palmer et al, 2009;Calaforra and De Waele, 2011). However, morphological evidence for subaerial corrosion including cupolas, megascallops, domes, vents, niches, notches, and other features can be found in many sulfidic caves, suggesting that subaerial SAS may be more widespread than generally considered (Audra et al, 2007;Audra et al, 2009;Plan et al, 2012;Temovski et al, 2013). In early work in Frasassi, Galdenzi (1990) proposed a model for cavern development in the Frasassi cave system in which both subaerial and subaqueous processes were important.…”

Az utóbbi 20 év barlangkutatási eredményei a Budai-hegységben (különös tekintettel a Rózsadomb környékére)

“…A karbonátkiválás ak -kor indulhatott meg, ami kor a vízszint felett már levegős részek is voltak, azaz már megvolt a lehetőség a vízben oldott CO 2 eltávozására ("ki gá zosodás") és a párolgásra (a vadózus zónában, a jára tok főtéjén kondenzvíz korrózióra és gömbfülkék képző désére, vö. MÜLLER 1974;SZUNYOGH 1982SZUNYOGH , 1984SZUNYOGH , 1989KRAUS 1993;AUDRA et al 2007). A karbonátos kőze tek oldó dása és a kigázosodás eredmé nyeként a víz fokoza tosan túltelítetté vált.…”

“…Az üreg fal felületén le csorgó, kezdetben még agresszív, telítetlen vízfilm azonban lejjebb, a tóhoz közeledve egyre melegebb kőzet -felületen, fokozatosan túltelítetté válik, és a vadózus zóna alsóbb járatszakaszain, a CO 2 -kigázosodás és párolgás követ kez tében, borsókőként válik ki belőle a CaCO 3 (pl. AUDRA et al 2007). A rózsadombi barlangok borsóköveinek létrejöttéért főként az (1) és (4) folyamatok lehetnek felelősek (l. még MÜLLER (1974) és KRAUS (1993) mo delljeit).…”

Corrosion morphology and cave wall alteration in an Alpine sulfuric acid cave (Kraushöhle, Austria)

“…Cunningham et al, 1995;Palmer and Palmer, 2000;Galdenzi, 2001;Forti et al, 2002;Audra et al, 2007Audra et al, , 2009aAudra et al, , 2009b.…”