Speleology Commons^™

Cryogenic Ridges: A New Speleothem Type, Bogdan P. Onac, Daniel M. Cleary, Oana A. Dumitru, Victor J. Polyak, Ioan Povara, Jonathan G. Wynn, Yemane Asmerom

International Journal of Speleology

Cryogenic cave carbonates have been described from several formerly or presently glaciated karst caves. In most of these occurrences, they precipitated as loose grains or aggregates with various morphologies and sizes. Here, we report on a new speleothem type (cryogenic ridges) identified in Sohodoalele Mici Cave (SW Romania) within a large chamber near the entrance shaft. This study was motivated by the presence of a network of calcite ridges over the stalactites’ surface and by the observation that during winter, these speleothems are covered by a thin ice layer. The higher δ¹⁸O (−3.5 to –1‰) and …

Chemical Characterization Of Clastic Cave Sediments And Insights Into Particle Transport And Storage In Karst Aquifers, Jill L. Riddell

Graduate Theses, Dissertations, and Problem Reports

Abstract

Chemical characterization of clastic cave sediments and insights into particle transport and storage in karst aquifers

Jill L. Riddell

Cave sediments can be divided into two groups: precipitates and clastics. Precipitates are speleothems, or lithologic or mineral features that are chemically precipitated in the cave environment. Clastic cave sediments are frequently described by depositional facies, sorting, and particle size (Bosch and White, 2004). Robust analytical chemical analyses of these sediments to quantify their physical and chemical components is rarely performed although some chemical characterization of mineralogy and paleomagnetism has become prevalent in recent years (Chess et al., 2010; Sasowsky …

On Biospeleothems From A Venezuelan Tepui Cave: U-Th Dating, Growth Rates, And Morphology, Joyce Lundberg, Charles Brewer-Carías, Donald A. Mcfarlane

International Journal of Speleology

Seven silica biospeleothems from Cueva Charles Brewer, Chimantá Plateau, Venezuela have been successfully U-Th dated despite very low U and high detrital Th concentrations. Growth rates are low, between ~100 to ~800 µm/ka, and are greater closer to water level. Dates in unaltered material are in good stratigraphic order, but secondary silicification may compromise the U-Th system, yielding unreliable sequences of ages. Detritally-enriched layers correlate with global climate cycles of the Late Quaternary, in particular the cooler, drier phases of MIS 5d, 5a, and 4. SEM studies indicate that the peloidal material is made up of silica nano-particles assembled to …

Phosphate Speleothems In Caves Developed In Iron Ores And Laterites Of The Carajás Mineral Province (Brazil) And A New Occurrence Of Spheniscidite, Alan R.L. Albuquerque, Rômulo S. Angélica, Daniele F. Gonçalves, Simone P.A. Paz

International Journal of Speleology

The Carajás Mineral Province has one of the largest concentrations of caves in Brazil, and its iron ore is among the country’s main exports. As a result of iron ore intense extraction, new environmental policies have been implemented. In an attempt to balance economic activity and environmental conservation, an inventory and a relevance-based classification of caves were implemented in 2008 as criteria for environmental licensing of mining ventures. This implementation motivated the present study of phosphate speleothems in Carajás’ caves developed in ferriferous rocks. The objectives of this study are to describe the phosphate minerals and their formation processes based …

Timing Of Speleogenesis Of Las Karmidas Cave (Mexico): First Description Of Pseudokarst Developed In Ignimbrite, María Del Pilar Aliaga-Campuzano, Rafael López-Martínez, Pablo Dávila-Harris, Ramón Espinasa-Pereña, Adriana Espino Del Castillo, J.P. Bernal

International Journal of Speleology

Las Karmidas Cave (Puebla State, Mexico) is an unusual type of pseudokarstic cavity generated by piping and erosive processes within the contact of a diamicton and an overlying Quaternary ignimbrite. Morphological evidence suggests that the cave was developed in two stages: a phreatic stage and a vadose stage. The latter was characterized by the formation of carbonate speleothems. The absolute upper-age limit for the cave (168 +7.1/-7.5 ka) was established by U-Th dating of zircons grains extracted from the overlying ignimbrite, whilst a minimum age for the transition from a phreatic to vadose regime (95.6 ± 2.1 ka) was constrained …