No description available.

The Waitomo Caves attract approximately 500 000 tourists each year. A requirement of tourist cave management is that the partial pressure of carbon dioxide (PCO₂) is kept below levels that are: hazardous to the health of visitors, hazardous to the glowworms and other natural inhabitants, or potentially corrosive to speleothems. For the Glowworm Cave at Waitomo, the maximum permissible PCO₂ level is 2400 ppm. When exceeded, the tourist operators are required to close the cave. Ten years of monitoring data at the Glowworm Cave was analysed. Most of the variation in PCO₂ could be attributed to CO₂ respired by tourists, and the mixing of cave air with lower PCO₂ outside air. Occasionally, there were periods with high PCO₂ levels while the cave was closed to tourists. The main objective of this study was to investigate the potential role of the Waitomo Stream in contributing CO₂ to the Glowworm Cave atmosphere. Analysis of ten years of Glowworm Cave monitoring data showed that the 2400 ppm PCO₂ limit was, on average, exceeded five times each year, with a total of 48 events between 1998 and 2007. Of the PCO₂ limit exceedences, approximately 31% of events were largely driven by high tourist numbers; 27% of PCO₂ limit exceedences were mainly driven by increased discharge, rainfall, and/or a low temperature gradient between the cave and outside air, whilst 29% of the PCO₂ limit exceedences were due to a combination of tourists and increased discharge, rainfall, and/or a low temperature gradient. The remaining 13% of exceedences were unexplained by tourists or the factors investigated. It may be that the unexplained exceedences were due to the night time closure of the cave door, restricting air exchange. The PCO₂ of the Waitomo Stream was measured by equilibrating air with the streamwater within a closed loop. The air was passed continuously through an infrared gas analyser (IRGA). The streamwater PCO₂ typically ranged between 600 - 1200 ppm. Fluctuations in the PCO₂ of the Waitomo Stream coincided with PCO₂ fluctuations in the Glowworm Cave air, and under most conditions, the stream probably acted as a sink for cave air CO₂. However, following rainfall events, the stream PCO₂ increased, exceeding cave air PCO₂, thus acting as a source of CO₂ to the cave air. High stream PCO₂ often occurred at times when air flow through the cave was restricted, e.g. when the temperature gradient between the cave air and outside air was low, or stream levels were high, thus limiting air movement. The combination of high stream PCO₂ and a low temperature gradient increased the likelihood of high cave air PCO₂. Dripwater was measured to determine whether an increase in dripwater PCO₂ occurred in response to rainfall events. When rainfall events resulted in increased discharge, the dripwater PCO₂ sometimes increased (occasionally exceeding 5000 ppm), however the pattern was not consistent. The chemistry of the Waitomo and Okohua (Ruakuri) Streams was monitored with daily samples collected and analysed for major ions: HCO₃ -, Ca²⁺, Na⁺ and Mg²⁺, and δ¹³C stable isotope. The HCO₃ -, Ca²⁺, Na⁺ and Mg²⁺ concentrations in the streamwater decreased with increased discharge, presumably due to dilution. Increased discharge following rainfall events correlated with increasing PCO₂ in the Waitomo Stream, suggesting that soil atmosphere CO₂ dissolved in soil waters, and carried to the stream by saturated flow, was responsible for the streamwater PCO₂ increase. Ca in the stream showed both an increase and a decrease with respect to rainfall. Increased Ca in the stream occurred at times when the discharged waters were coming from the phreatic zone, and thus sufficient time had lapsed for CO₂ in the discharge waters to react with the limestone (carbonate dissolution reaction). Decreased Ca occurred when the infiltration and percolation of rainwater was rapid, and thus the streamwater was characterised by a higher PCO₂ and a lower Ca concentration, as insufficient time had lapsed for the discharge waters to equilibrate with the limestone. Increased negativity in the δ¹³C of the Waitomo and Ruakuri Streams coincided with increased discharge. During summer low flow, the δ¹³C of Waitomo Stream waters was -11.3‰, whereas during high stream discharge events, the δ¹³C dropped to -12 - -14‰. The δ¹³C of limestone is 0‰, the atmosphere is -7‰, and the soil atmosphere is reported to be about -24‰, thus the decrease in δ¹³C during high flow events supports the contention that soil atmosphere CO₂ is a likely source of the increased CO₂ in flood waters.

The interaction between climate, environments, and mammalian faunas during the late Pleistocene-Holocene has been studied intently over the last several decades. Cave deposits play an important role in our understanding of these complex interactions, but they are especially significant for our understanding of the faunal history of the Great Basin. In order to develop a deeper time perspective on mammalian faunal change, I began a project that integrated several elements necessary for identifying and interpreting biotic change in the Great Basin of the western United States. These elements included development of a framework for understanding the importance of cave deposits for the paleontological record, collection of a mammalian fauna that pre-dates the terminal Pleistocene, identification of that fauna in the midst of shifting taxonomic paradigms, and evaluation of the fauna in the context of previous regional biogeographic models. I utilized data from the FAUNMAP database to evaluate the significance of the contribution that cave deposits make to the Pleistocene mammal record. Caves do provide unique faunal data in addition to contributing a high percentage of the individual species records for late Pleistocene mammals. Fieldwork was conducted at Cathedral Cave, NV, in order to assess a fauna that was thought to predate the late Pleistocene-Holocene transition. In excess of 30,000 identifiable fossils were recovered in an excavation area that was roughly 1.5 x 2 x 0.7 m. Prior to fieldwork in 2003, age estimates for the fauna were between 750 ka to 850 ka. New chronologic analyses suggest a more recent age (≤146.02±2.584 ka to 151.2±4.4 ka) that extends the known chronologic distributions of several taxa and alters previously established biochronologic frameworks for the Pleistocene. This work also calls into question previous age assignments for portions of Smith Creek Cave. Individual faunal identifications were made using a conservative data-reliant approach in order to minimize geographic assumptions and render an independent data set useful for broad biogeographic analyses. Although the faunal data presented here do not explicitly support or refute regional biogeographic models, they do indicate that patterns of faunal change can be found even when species-level identification are not achieved.

Microbial communities influence the kinetics and pathways of reactions involved in the dissolution of a number of minerals (Ehrlich 1996). On a smaller scale these interactions can affect substrate permeability, porosity, and create highly localized biogeochemical conditions. However, a mechanistic understanding of the consequences of microbial surface colonization on calcite dissolution rate has yet to be achieved. More specifically, little is known about the impact of sulfur-oxidizing bacteria activity on the rate of carbonate mineral dissolution, or the nature of the microbe-limestone attachment and interaction. Through a series of laboratory and field experiments the effect of mineral surface colonization by microbial communities, obtained from an active sulfuric acid cave (Lower Kane Cave (LKC), Big Horn Basin, WY), on the dissolution rate of Madison Limestone was quantified. Results from laboratory experiments showed that a microbial biofilm, composed primarily of Epsilonproteobacteria and Gammaproteobacteria growing on a limestone surface oxidized thiosulfate and increased carbonate dissolution rates up to 3.3 times faster than abiotic rates. When all thiosulfate substrate was withheld the community oxidized stored intracellular sulfur, continuing to accelerate limestone dissolution and decreasing pH. This process is sensitive to O2 limitations. Characterization of this aggressive sub-biofilm corrosion was more closely examined by SEM imaging. By comparing mineral surface morphology of colonized chips to non-colonized chips of various carbonate substrates, it was shown that even under conditions near equilibrium with calcite, aggressive dissolution of carbonate substratum occurs exclusively beneath the biofilm. These findings support the hypothesis that (1) sulfur-oxidizing microbial communities aggressively dissolve carbonates in order to buffer the production of excess acidity by neutrophilic communities and (2) biofilm presence affects carbonate mineral dissolution by physically separating a bulk stream water from the sub-biomat environment. Furthermore, it was found that mineralogy affects the degree of establishment of microbial communities in this environment. Results from a series of four laboratory and one in situ reactor experiment showed that limestone and dolostone substratum consistently had higher biomass accumulations than silicate minerals or pure Iceland spar calcite in the same reactor. These results provide evidence to support the hypothesis that mineralogy influences microbial accumulation in sulfuric-acid karst systems. Particularly, neutrophilic sulfur-oxidizing communities accumulate in greater quantities on solid substrates that buffer metabolically-generated acidity. These results also demonstrated the dependence of microorganisms on colonization of a particular mineral surface, possibly in order to gain access to micronutrients bound within solid substrates when exposed to nutrient-limited conditions. / text

Upper Palaeolithic cave art research has tended to focus on the images themselves, rather than the physical and social circumstances of their production. This dissertation explores and develops new practice-based ways of investigating cave art. A method analysing features of the cave environment, such as light, space and accessibility, internal conditions etc., and how these relate to traces of human activity, is developed and applied to three decorated caves from Upper Palaeolithic in southern France: Marsoulas (Haute-Garonne), Chauvet (Ardèche) and Rouffignac (Périgord). New insights are suggested into the underlying practice of cave art and its significance in Upper Palaeolithic societies. / La recherche l’art rupestre Paléolithique supérieur a eu tendance à se focaliser sur les images elles-mêmes, plutôt que les circonstances physiques et sociales de leur production. Cette dissertation explore et développe des nouvelles formes d’investigation de l’art rupestre basées sur la pratique. Une méthode pour analyser des caractéristiques de l’environnement de la grotte, comme la lumière, l’espace et l’accessibilité, des conditions internes etc., et comment ceux-ci sont associés à des traces de l’activité humaine, est développée et appliquée à trois grottes de l’époque Paléolithique supérieur dans le sud de France: Marsoulas (Haute-Garonne), Chauvet (Ardèche) et Rouffignac (Périgord). Une nouvelle vision est suggérée pour la pratique sous-jacente de l’art rupestre et son importance dans les sociétés paléolithiques.

Thesis (M.S.)--Missouri State University, 2009. / "May 2009." Includes bibliographical references (leaves 58-61). Also available online.

No description available.

Flank margin caves are karst features that develop in the freshwater/saline mixing zone within the carbonate islands of the Bahamas. The flank margin caves that are currently exposed developed during the last interglacial sea level highstand (+6 m; ~125 ka). Initially small ovid chambers, the caves increase in size to about 100 m2, then interconnect with adjacent chambers to form medium-sized caves. At about 1000 m2, these medium-size caves interlink forming large caves that are laterally extensive, vertically restricted, do not penetrate the fresh-water lens a significant amount, and run parallel to the axis of the ridge in which they formed. Small caves have a much smaller area to perimeter ratio than do large caves. As cave chambers grow and interconnect, perimeters become much more complex, and the number of bedrock columns in the cave increases. These results have implications for water resource management, and porosity modeling.

Caves on carbonate islands are useful indicators of past sea level because cave formation is dependent on sea-level controlled freshwater lens position (flank margin caves), or form in direct contact with coastal processes (sea caves). Sea-level curves present a useful proxy for glacioeustatic and paleoclimate studies, so caves offer useful data. Once a flank margin cave is breached, it may be modified and eroded by waves. This overprinting leads to morphology similar to that of sea caves. While both indicate past sea level, they reveal differing information about the amount of denudation that has occurred to expose them (a paleoclimate indicator), so differentiation of these cave types is important. This study presents some of the first sea cave data from carbonate islands, and makes morphological comparisons between flank margin caves and sea caves from the Bahamas, California, and Maine. Using morphometric techniques, these caves can be distinctly identified.

The importance of ants as elements in cave ecology has been mostly unrecognized. A global list of ant species recorded from caves, compiled from a review of existing literature, is presented. This paper also reviews what is currently known about ants occurring in Arizona ( USA) caves. The diversity and distribution represented in these records suggests ants are relatively common cave visitors (trogloxenes). A general utilization of caves by ants within both temperate and tropical latitudes may be inferred from this combined evidence. Observations of ant behavior in Arizona caves demonstrate a low level and sporadic, but persistent, use of these habitats and their contained resources by individual ant colonies. Documentation of Neivamyrmex sp. preying on cave-inhabiting arthropods is reported here for the first time. Observations of hypogeic army ants in caves suggests they may not penetrate to great vertical depth in search of prey, but can be persistent occupants in relatively shallow, horizontal sections of caves where they may prey on endemic cave animals. First cave records for ten ant species are reported from Arizona caves. These include two species of Neivamyrmex (N. nigrescens Cresson and Neivamyrmex sp.; Formicidae: Dorylinae), four myrmicines (Pheidole portalensis Wilson, Pheidole cf. porcula Wheeler, Solenopsis aurea Wheeler and Stenamma sp. Westwood), one dolichoderine (Forelius keiferi Wheeler) and three formicines (Lasius arizonicus Wheeler, L. sitiens Wilson, and Camponotus sp. Mayr).