Assessing Humidity in an Upper Pleistocene Karst Environment: Palaeoclimates and Palaeomicroenvironments at the cave Divje babe I, Slovenia, 2002, Turk Ivan, Skaberne Dragomir, Blackwell Bonnie A. B. , Dirjec Janez

The article presents a new sedimentary-climatic model for explaining autochthonous clastic sediment in the Upper Pleistocene site, Divje babe I, Slovenia. The sediment analysed here was deposited during Oxygen Isotope Stages 1, 3 and 5 (OIS, OIS 3, OIS 5). The stress is on precipitation, which we explained on the basis of the quantity of authigenic structural aggregates in the sediment. We supported the results with quantitative analysis of clasts with etched surface, which represent corrosion of the cave ceiling, and etched bones, which represent corrosion on the cave ground. We also analysed the relation between climate and cave bears, and Neanderthals and climate, on the basis of mass fossil remains and finds of artefacts. All analyses were made on the basis of three-dimensional sampling, i.e., in horizontal and vertical directions. We sampled 65 profiles over an area of 65 m2. Each profile had 35 arbitrary stratigraphic units (splits) with data on aggregates, etched bones, fossil remains and artefacts. In explaining the sediment characteristics that point to climatic parameters, we consistently took into account the Holocene standards for the site. We found that the climate in OIS 3 was colder and damper than in OIS 1 and OIS 5. People and animals responded to the climatic changes in OIS 3 with more visits to the cave, but not at the same time. The climatic change was presumably reflected in the microlocation of the cave mainly by the longer duration of snow cover.

Soil types and eolian dust in high-mountainous karst of the Northern Calcareous Alps (Zugspitzplatt, Wetterstein Mountains, Germany), 2003, Kufmann C. ,

This, study deals with the soil formation on pure limestone in the high-mountainous karst of Wetterstein Mountains (Northern Calcareous Alps). The study area in detail covers the alpine (2000 to 2350 in) and the subnivale zone (2350 to 2600 in) of Zugspitzplatt, a tertiary paleosurface situated next to the highest summit of Germany (Zugspitze 2963 in). The formation of autochthonous soils is determined by the following parameters: uniform geology and geochemistry of Triassic limestone (CaCO3 MgCO3 greater than or equal to 98%), variable substrata (solid rock, debris, local moraine), hypsometric pattern of vegetation modified by microclimate and aspect, variety of micro-environments in karst relief. In the subnivale zone, only leptosols (lithic, skeletic) and regosols (calcaric, humic) occur, whereas in the alpine zone different stages of folic histosols and rendzic leptosols prevail due to the diversity of vegetation. The purity of limestone prevents a distinct contribution of residues to soil formation. Instead of expected A-B-C profiles, the residues are mixed with organic matter of folic horizons (O-OB-C). Only in karst depressions or on local moraines small Bt horizons (2 to 5 cm) occur. They mark a developed stage of folic histosol (O-OB-Bt-C) representing the climax of autochthonous mineral soil genesis in the study area. Special features are brown deposits (mean thickness 30 cm) covering large parts of the alpine zone. On the basis of mineralogical (X-ray diffraction, heavy minerals) and pedological data (grain size, soil chemistry), eolian origin is indicated. The resulting soils are classified as loess loam-like cambisols (Ah-Bw-2(Bt)-2C) and are related to late glacial loess deposition (Egesen-Stade of Younger Dryas). The abundance of mica and silt in the surface layers and the grain size distribution of snow dust samples prove that dust influx by southerly winds is still continuing. The major sources for both late glacial and present-day dust are magmatic and metamorphic rock formations of the Central Alps. Additionally, local dust transport from adjacent outcrops of Jurassic and Lower Cretaceous sediments is evident. (C) 2003 Elsevier Science B.V. All rights reserved

High 222Rn levels in a show cave (Castanar de Ibor, Spain): Proposal and application of management measures to minimize the effects on guides and visitors, 2006, Lario J. , Sanchezmoral S. , Cuezva S. , Taborda M. , Soler V. ,

Castanar de Ibor (Caceres, Spain) is a low energy cave showing very high micro-environmental stability throughout the annual cycle and minimum rates of energy exchange with the atmosphere. The radon (222Rn) levels monitored inside Castanar cave reached 50,462 Bq m-3 in April 2005 and had an annual average of 32,246 Bq m-3. Annual variations in Rn concentration seem mainly related to differences in internal and external temperature. The highest values of 222Rn concentration occur during winter and early spring when air-cave temperature surpasses the external air temperature, evidencing very low air exchange rate. These values are the highest recorded in any Spanish cave, either natural or show, and are much higher than the average in most caves around the world. The calculation of the effective dose received by guides during 2004 showed values higher than the maximum effective dose recommended by authorities. Two management measurements were applied to reduce these doses: reduction of the time of visit to a maximum of 60 min, and opening the cave door 1 hour before the entrance of the guides and visitors. These management measures were effective, as they led to a decrease of 10-12% in 222Rn in the cave atmosphere during visits and prevented the guides from being exposed to higher than recommended doses of radiation