International Journal of Speleology

ISSN 0392-6672
Contact: Jo De Waele geoam@unica.it 
Website: http://www.ijs.speleo.it/

Recent issue: January-July 2005, 34 (1-2)

Cigna, A, A. 2005. Radon in caves
International Journal of Speleology, 34 (1-2), 1-18. Bologna (Italy). ISSN 0392-6672.

The physical characteristics of radon are reported as well as its sources, the transport in rock and its behaviour in caves. Then, the instruments, both active and passive, used for the measurement of radon concentration are discussed by taking into account their respective advantages and disadvantages for the use in the cave environment. Since in many countries radon is the object of regulations that were adopted for radiation protection purposes, this aspect is examined and the recommendations issued by international organisations and enforced in different countries are reported. Materials, methods and other remarks on the limits implementation are also listed with the aim of providing the managers of show caves with some instruments to comply with the domestic requirements with the most convenient solution.

Arbea, J, I. 2005. AGRAPHORURA CALVOI n. sp. from Venezuelan caves (Collembola: Onychiuridae)
International Journal of Speleology, 34 (1-2), 19-24. Bologna (Italy). ISSN 0392-6672.

A new species of Agraphorura (Collembola: Poduromorpha: Onychiuridae) from caves in the North-West of Venezuela is described. A. calvoi n. sp. can be distinguished from its congeners by the following combination of characters: antennal organ III with four papillae, 32/133/33343 dorsal pseudocellar formula, 3/000/0112 ventral pseudocellar, subcoxae each with two pseudocelli, postantennal organ with 7-9 vesicles, unguiculus with a basal lamella, tibiotarsi I-III with 19,19,18 setae (distal whorl of 9 setae). A table with the differential characters, as well as an identification key for all of the known species of Agraphorura are provided.

Dublyansky Y. V. and Smirnov S. Z. 2005. Cavity-based secondary mineralization in volcanic tuffs of Yucca Mountain, Nevada: a new type of the polymineral vadose speleothem, or a hydrothermal deposit?
International Journal of Speleology, 34 (1-2), 25-44. Bologna (Italy). ISSN 0392-6672.

Secondary minerals (calcite, chalcedony, quartz, opal, fl uorite, heulandite, strontianite) residing in open cavities in the Miocene rhyolite tuffs of Yucca Mountain, Nevada have been interpreted by some researchers as "speleothemic" formations, deposited as a result of downward infiltration of meteoric waters (DOE, 2001, Whelan et al., 2002). The major mineral of the paragenesis, calcite, shows spectacular trend of the textural and crystal morphology change: from anhedral granular occurrences, through (optional) platelet, bladed and scepter varieties, to euhedral blocky morphologies. The trend is consistent with the overall decrease in the supersaturation of the mineral forming solution. Stable isotope properties of calcite evolve from 13C-enriched (δ13C = +4 to +9 ‰ PDB) at early stages of growth to 13C-depleted (-5 to -10 ‰) at late stages. The non-cyclic character of the isotope record and extreme variations of isotopic values argue against the meteoric origin of mineral forming fluids. The δ13C >4 ‰ PDB require isotope partitioning between dissolved CO2 and CH4, which is only possible in reducing anoxic environment, but not in aerated vadose zone.

Fluid inclusions studied in calcite, quartz and fluorite revealed that the minerals were deposited from thermal solutions. The temperatures were higher at early stages of mineral growth (60 to 85oC) and declined with time. Most late-stage calcites contain only all-liquid inclusions, suggesting temperatures less than ca. 35-50oC. Minerals collected close to the major fault show the highest temperatures. Gases trapped in fluid inclusions are dominated by CO2 and CH4; Raman spectrometry results suggest the presence of aromatic/cyclic hydrocarbon gases. The gas chemistry, thus, also indicates reduced (anoxic) character of the mineral forming fluids.
Secondary minerals at Yucca Mountain have likely formed during the short-term invasion(s) of the deep-seated aqueous fluids into the vadose zone. Following the invasion, fluids, initially equilibrated with the deep (reduced, anoxic) environment, evolved toward equilibrium with the new environment (cooling, degassing, mixing with shallow oxidizing waters, etc.). While some features of mineralization are compatible with the "speleothemic" or "meteoric infiltration" model, most of the evidence does not lend itself to rational explanation within this model.

Klimchouk, A. 2005. Conceptualisation of speleogenesis in multi-storey artesian systems: a model of transverse speleogenesis.
International Journal of Speleology, 34 (1-2), 45-64. Bologna (Italy). ISSN 0392-6672
(Re-published from "Speleogenesis and Evol. of Karst Aquifers", 1 (2), 2003).

Conceptual and respective quantitative models of speleogenesis/karstification developed for unconfined aquifers do not adequately represent speleogenesis in confined settings. A conceptual model for speleogenesis in confined settings is suggested, based on views about hydraulic continuity in artesian basins and close cross-formation communication between aquifers in multi-storey artesian systems. Soluble units sandwiched between insoluble porous/fissured formations (common aquifers) initially serve as low permeability beds separating aquifers in a confined system. Conduits evolve as result of vertical hydraulic communication between aquifers across the soluble bed ("transverse speleogenesis"). Recharge from the adjacent aquifer is dispersed and uniform, and flow paths across the soluble bed are rather short. There is a specific hydrogeologic mechanism inherent in artesian transverse speleogenesis (restricted input/output) that suppresses the positive flow-dissolution feedback and hence speleogenetic competition in fissure networks, and accounts for the development of more pervasive channelling in confined settings, of maze patterns where appropriate structural prerequisites exist. This is the fundamental cause for the distinctions between cave morphologies evolving in unconfined and confined aquifers and for eventual distinctions of karstic permeability, storage characteristics and flow system behaviour between the two types of aquifers.

Passage network density (the ratio of the cave length to the area of the cave field, km/km2) and cave porosity (a fraction of the volume of a cave block, occupied by mapped cavities) are roughly one order of magnitude greater in confined settings than in unconfined. Average areal coverage (a fraction of the area of the cave field occupied by passages in a plan view) is about 5 times greater in confined settings. Conduit permeability in unconfined settings tends to be highly heterogeneous, whereas it is more homogeneous in confined settings. The storage characteristics of confined karstified aquifers are much greater.

Recognition of the differences between origin, organisation and behaviour of karst systems evolved in unconfined and confined settings can improve efficiency of exploration and management of various resources in karst regions and adequacy of assessment of karst-related hazards.

Häuselmann, Ph. 2005. Cross-formational flow, diffluence and transfluence observed in St. Beatus Cave and SiebenHengste (Switzerland).
International Journal of Speleology, 34 (1-2), 65-70. Bologna (Italy). ISSN 0392-6672
(Re-published from "Speleogenesis and Evol. of Karst Aquifers", 1 (2), 2003).

Observations in St. Beatus Cave and neighbouring caves revealed complex water flowpaths that can be used for explaining the behaviour of tracing experiments. The observations prove that even in vadose conditions, cross-formational flow, diffluences and transfluences are a quite common feature. Therefore, also the vadose karst has a very complex  organisation.

Osborne, R. A. L. 2005. Partitions, Compartments and Portals: Cave Development in internally impounded karst masses.
International Journal of Speleology, 34 (1-2), 71-81. Bologna (Italy). ISSN 0392-6672
(Re-published from "Speleogenesis and Evol. of Karst Aquifers", 1 (4), 2003).

Dykes and other vertical bodies can act as aquicludes within bodies of karst rock. These partitions separate isolated bodies of soluble rock called compartments. Speleogenetically each compartment will behave as a small impounded-karst until the partition becomes breached. Breaches through partitions, portals, allow water, air and biota including humans to pass between sections of caves that were originally isolated.

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