During a trip to the Hall of the White Giant, Carlsbad Caverns (NM, USA) cigar-shaped vertically upward developing holes were observed on the ceiling at different heights of the passages. They have a circular cross-section with diameters of 1 to some centimetres and taper out towards their upper end. Their walls are smooth and their bottom edges sharp, while their length can reach several decimetres. Sometimes gypsum can be found inside. They often occur randomly distributed in groups and their development is not necessarily controlled by fractures or other bedrock structures. We name these peculiar karren-like cave microforms “zenithal ceiling tube-holes” because of their origin by H2S environment corrosion processes and their vertical (zenithal) upward growth in ceilings. A comparison is made between zenithal ceiling tube-holes and other karstic or non karstic similar forms such as bellholes, oxidation vents, snailholes, Korrosionskolke (mixture-solution hollows) or pockets, röhrenkarren, light-oriented photokarren, borings of (often marine) organisms and negative stalactites. Zenithal ceiling tube-holes are created by the corrosive effect of sulphuric acid. H2S(g) dissolves in water giving rise to widespread sulphuric acid corrosion. When H2S bubbles are trapped underneath overhanging surfaces or ceilings and water level rises steadily the corrosive effect is concentrated vertically upwards, drilling vertical holes that can also completely pass overhanging rock ledges.
New peculiar cave ceiling forms from Carlsbad Caverns (New Mexico): the zenithal ceiling tubeholes / Calaforra J.M.; De Waele J.. - In: GEOMORPHOLOGY. - ISSN 0169-555X. - STAMPA. - 134:(2011), pp. 43-48. [10.1016/j.geomorph.2011.02.032]
New peculiar cave ceiling forms from Carlsbad Caverns (New Mexico): the zenithal ceiling tubeholes
DE WAELE, JO HILAIRE AGNES
2011
Abstract
During a trip to the Hall of the White Giant, Carlsbad Caverns (NM, USA) cigar-shaped vertically upward developing holes were observed on the ceiling at different heights of the passages. They have a circular cross-section with diameters of 1 to some centimetres and taper out towards their upper end. Their walls are smooth and their bottom edges sharp, while their length can reach several decimetres. Sometimes gypsum can be found inside. They often occur randomly distributed in groups and their development is not necessarily controlled by fractures or other bedrock structures. We name these peculiar karren-like cave microforms “zenithal ceiling tube-holes” because of their origin by H2S environment corrosion processes and their vertical (zenithal) upward growth in ceilings. A comparison is made between zenithal ceiling tube-holes and other karstic or non karstic similar forms such as bellholes, oxidation vents, snailholes, Korrosionskolke (mixture-solution hollows) or pockets, röhrenkarren, light-oriented photokarren, borings of (often marine) organisms and negative stalactites. Zenithal ceiling tube-holes are created by the corrosive effect of sulphuric acid. H2S(g) dissolves in water giving rise to widespread sulphuric acid corrosion. When H2S bubbles are trapped underneath overhanging surfaces or ceilings and water level rises steadily the corrosive effect is concentrated vertically upwards, drilling vertical holes that can also completely pass overhanging rock ledges.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.