Limestone Caverns Research Articles

From room acoustics to paleoacoustics: A preliminary acoustical study in Chauvet Cave

Due to geological closures between 21 000 and 29 000 years ago, the acoustics of the UNESCO World Heritage site, Chauvet Cave (Ardèche, France) have been in slow flux via mineral deposition processes that continue to alter its interior. Since Upper Paleolithic humans created extensive and elaborate artworks throughout this grand limestone cavern more than 30 000 years ago, the cave’s interior has changed with calcite and other minerals forming a diversity of features including the best-known stalactites, stalagmites, and flowstone floor coverings. Here, we report on archaeoacoustics fieldwork in 2022 that initiated acoustical mapping and reconstructive modeling to enable archaeological acoustics research and the creation of auralizations and multimodal experiences for virtual public access to this conservation-restricted place. We present here a comparative room acoustics study of two substantively enclosed cave areas (Salle du Fond and Galerie du Cactus) whose volumes differ significantly, but whose extant reverberation times are similar across most center bands, providing important information about the dynamical contributions of surface materials and structural features distinct to each impulse-response-measured location. Our study exemplifies an archaeological application of room acoustics methods with site-responsive techniques that offer a human-centered approach for understanding and translating cultural heritage acoustics across time.

Climate and vegetation and their impact on stable C and N isotope ratios in bat guano

Cave guano deposits represent a relatively untapped paleoecological archive that can provide information about past vegetation, climate, and bat diet over several millennia. Recent research suggests that carbon isotope values (δ13C) measured in guano accumulations from insectivorous bats reflect the relative abundance of C3 and C4 plants on the landscape while nitrogen isotope values (δ15N) may reflect precipitation amount. Together, these proxies can provide useful information for restoration practitioners seeking to understand how plant species composition has changed over time in relation to climate and land use. To better calibrate these proxies for use in restoration, we compared instrumental records of precipitation and satellite imagery of vegetation with isotope values measured in modern bat guano from Mary Lawson Cave, a large limestone cavern located in central Missouri. Mary Lawson Cave hosts a maternity colony of insectivorous gray bats (Myotis grisescens), and as such, contains significant guano accumulations. In the fall of 2018, we collected a 60 cm long guano core that dates to 1999 cal AD at its base. Guano core δ13C values decrease from the base toward the surface (from ~-26 to -27‰) whereas δ15N values increase toward the surface even after accounting for ammonia volatilization (from ~3 to 5‰). Presently, the landscape around Mary Lawson Cave is dominated by a deciduous forest and pasture. Given that the land cover has changed very little over this period, the decline in δ13C values toward the present likely reflects a shift in land management on farms and/or increases in invasive C3 species. Rainfall amounts from nearby Lebanon, Missouri, are significantly positively correlated with guano δ15N values, a relationship that is notably opposite that observed previously in soil and plants. We argue that heavy fertilizer application and significant grazing intensity could lead to the accumulation of large pools of excess labile nitrogen which would be vulnerable to leaching during precipitation events. The relationship between guano δ15N values and precipitation may differ for materials from less agriculturally impacted locations or periods and should be extended into the past with caution.

The Orchid Flora of Barra Honda National Park, Nicoya, Guanacaste, Costa Rica

Barra Honda National Park (BHNP) lies in the Tempisque River Basin of the Península de Nicoya, Guanacaste, Costa Rica. The Park is well known for its limestone caverns, which date from the Upper Paleocene–Lower Eocene and are the main attraction of BHNP. The area shows a marked climatic seasonality with a predominantly semideciduous tropical dry forest. We present a floristic treatment of the orchids of BHNP based on field collections, herbarium sampling, and documentation of living specimens. We discuss the biodiversity, climate, geology, and topography of the Park and provide a novel vegetation zones map with eight floristic associations: bean plantations, disturbed secondary forest, evergreen forest, jaragua fields, mature secondary forests, pastures, rocky areas, karstic limestone pavement, and young secondary forest. For the 36 species belonging to 29 genera recorded, we provide composite line drawings and Lankester composite digital plates, descriptions, distribution, ecology, etymology, synonymy, taxonomy, photographs, and a key to the species for field identification based on morphology. Ten species of orchids (27.8%) are terrestrials and 26 are epiphytes (72.2%). The evergreen forest contains 80% of the orchid species of BHNP. We describe Pelexia barrahondaensis and Sarcoglottis calcicola as new to science, and we propose a new combination under Specklinia for Pleurothallis panamensis. Also, we record the terrestrial orchid genus Tropidia for the first time in Costa Rica. The present study provides new information on the Nicoya Peninsula's dry forest ecosystems for in situ conservation and research. This work can be useful for other protected areas within the same ecosystem that lack a floristic treatment of the Orchidaceae.

An extended finite element method for the prediction of acid-etched fracture propagation behavior in fractured-vuggy carbonate reservoirs

Acid fracturing is an important method of achieving high-efficiency economic development of carbonate reservoirs. The propagation of acid-etched fractures is affected significantly by geological discontinuities such as natural fractures and limestone caverns. Therefore, acid-etched fractures in carbonate reservoirs also differ greatly in morphology to those inhomogeneous reservoirs. However, no clear propagation mechanism has been available to describe and predict the propagation behavior of acid-etched fractures. In order to investigate the process, based on the extended finite element method, a set of acid-etched fracture propagation models for fracture-vuggy reservoirs, including mechanical, hydro and acid-rock reaction modules, were established. The effect of vuggy, natural fracture and acid on the initiation and propagation of induced fracture, the surface morphology of the acid-etched fractures, the effects of the number of perforation clusters, and natural limestone caverns, were considered. The calculated geometric size of the fracture was compared with the results based on the CGD (Christianovich-Geertsma-Daneshy model) model, for validating the reliability of the present model. The effects of the injection fracturing liquid type and the number of perforation clusters on fracture initiation position, propagation path, and surface morphology were evaluated. The calculation results also were compared with large-scale tri-axial physical experiment data. Finally, the fracture propagation behavior in rock samples containing natural fractures and limestone caverns was simulated in order to examine examining the effects of the limestone caverns with different sizes at different positions on the propagation path of acid-etched fractures. The interaction between induced fractures and limestone caverns was discussed. The induced fractures priority was given to activating natural fractures around the wellbore and extending along the natural fractures and tended to be deflected from the maximum horizontal principal stress direction due to the existence of caverns arrested fractures to a certain degree.

SALITRE: O PRODUTO QUÍMICO ESTRATÉGICO NO PASSADO DO BRASIL

SALTPETER: THE STRATEGIC CHEMICAL PRODUCT IN THE PAST OF BRAZIL. Saltpeter demanded for a long-time strategic attention in view of its importance in the form of gunpowder by the governments of many nations. The sources of this mineral in Brazil were almost always associated to the soil in caves, which was extracted because of a limited amount of that precious salt. The first references pointed out that saltpeter was first discovered in the São Francisco basin in regions of the south of the Captaincy of Bahia and in the north of Minas Gerais. Some historical documents show that the Serra do Baldim was the object of intensive mining activities of saltpeter from its caves and the product became the focus of conflicts and left scars on the walls of some limestone caverns.

Historical storage cellars in Budapest

The Kőbánya district of Budapest is situated on the eastern margins of the Hungarian capital city. Beneath Kőbánya there is an extensive limestone layer, in which tunnels and passages have been made, ‍some of which appear to date from the 13th century. In the 19th century, the limestone caverns of Budapest-Kőbánya were used for the refrigeration of perishable goods in large quantities. The caverns‍ represent one of Budapest’s historical industrial landmarks, although their architectural history has not been documented in full. This article analyses the architectural development of these evidently low-tech‍ facilities, while also exploring their significant role in the city’s urbanisation. The technical functions and structure of the system of caverns may be useful as a resource for society in the future when the supply‍ of fossil fuels runs out. The effectiveness of the caverns as places for refrigeration can be demonstrated through climatic calculations. The cavern system has significant energy capabilities, given that there is a‍constant air temperature throughout the year. The vast amount of geothermal energy could be used to cool heat pumps or heat exchangers. The results of measurements taken in preparation for this article are‍ presented.

Alcoholic pupfish kick breathing oxygen

Deep in a warm pool in a limestone cavern in the Mojave Desert lives one of the rarest species on earth: the Devils Hole pupfish (Cyprinodon diabolis). With a current population of just 131 adults, the race is on to secure the fish's future. ‘One possible cause for the small population size of C. diabolis is limited food availability’, says Frank van Breukelen from the University of Nevada Las Vegas, USA. Realising that the dark conditions dramatically limit the amount of food that grows in the cavern to support the fish, van Breukelen and his colleague, Stanley Hillyard, were curious to know how many pupfish the restricted ecosystem could sustain. However, before they could do the calculation, the duo needed to measure the scarce fish's metabolic rate. As the native Devils Hole pupfish population is too endangered to study directly, van Breukelen and Hillyard measured the metabolic rate of a refuge population of the fish that had been established as an insurance policy should the population ever be wiped out. But when they performed the measurement, the duo stumbled across an unexpected paradox.Recording the fish's oxygen consumption at temperatures ranging from 25 to 38°C, Matt Heuton found that they consumed oxygen at a stable rate of around 300 μl h−1 when they came from a population that had been raised at 28°C. However, when Heuton measured the oxygen consumption rate of fish raised at 33°C – the temperature in the Devils Hole spring – something went wrong. The fish appeared to stop consuming oxygen. ‘My initial reaction was that there was a malfunction of the electrode’, laughs van Breukelen. However, after testing 295 animals, van Breukelen and Hillyard had to concede that the phenomenon was real. The fish were somehow switching from aerobic metabolism to anaerobic metabolism, which was perplexing as anaerobic metabolism is nowhere near as effective as aerobic metabolism – only yielding 1/15 the amount of ATP per glucose molecule generated by aerobic metabolism. Why were the fish indulging in such a profligate practice?Intrigued, the team tested whether the phenomenon was the result of the refuge C. diabolis population breeding with another closely related species, Cyprinodon nevadensis mionectes. van Breukelen explains that it has been suggested that interbreeding with other pupfish could have compromised the function of the mitochondria that generate ATP. However, when the team measured the oxygen consumption patterns of the two species, they both performed paradoxical anaerobism, so there was no mitochondrial disruption. And when the team tested whether C. diabolis were switching to paradoxical anaerobism because they had depressed metabolism, they found that the fish were still wafting their gill covers to take in oxygen, so they weren't depressing their metabolism. Finally, the team checked whether C. diabolis were switching to paradoxical anaerobism because there simply was not enough oxygen to sustain aerobic metabolism in the warm conditions. However, even that theory did not hold water.‘We were going nuts trying to figure out what triggers paradoxical anaerobism’, admits van Breukelen, until he and Heuton embarked on an animated brain-storming session one night. It occurred to them that the fish may be switching to paradoxical anaerobism to avoid the toxic side-effects of aerobic metabolism, producing ethanol instead. They knew that the 33°C-acclimated fish naturally produced high levels of ethanol – 7.3 times more than the fish from cooler water: could the ethanol be switching off aerobic energy production and stalling oxygen consumption? ‘I said, “Let's get the fish drunk”’, recalls van Breukelen. And when the team added ethanol to the fish's water, even the fish that were adapted to cooler water switched to paradoxical anaerobism. So Devils Hole pupfish switch off aerobic metabolism to avoid the toxic side-effect of an aerobic lifestyle, despite the expense.

An approach for collection of nearfield groundwater samples in submerged limestone caverns

Walls of submerged caves feeding Florida springs are often lined with a heavy mat of filamentous bacteria, many of which are able to oxidize reduced sulfur in groundwater migrating from the porous bedrock into the cave conduit. To determine changes in water chemistry as water passes through the microbial mat, a simple device made from standard well screen and sealed with a rubber stopper and controllable vents was installed in a hole drilled in the wall of the cave passage. The sampler was sealed in place with marine epoxy. We measured anions in water from the sampler and from the water-filled conduit taken just outside the sampler. Most anions measured viz., Cl−, NO3−, and PO43−, increased slightly between the matrix and conduit waters. However, traces of sulfide were measured in the water from the rock matrix, but not in the conduit. SO42− concentrations in the conduit were about twice that measured in the water from the sampler, about 22 and 11 mg SO42− L−1, respectively, providing further evidence that sulfur oxidation is an important process in the bacterial mats attached to the limestone surfaces in these caves. An additional use of the sampling device is to measure discharge from the local bedrock into the cave conduit.Keywords: sulfur oxidation, bacteria, acid dissolution, groundwater chemistry.DOI:10.3986/ac.v42i2-3.664

Description and Ecology of A New Cavernicolous, Arachnophilous Thread- legged Bug (Hemiptera: Reduviidae: Emesini) from Kartchner Caverns, Cochise County, Arizona.

A new cavernicolous, arachnophilous thread-legged bug (Phasmatocoris labyrinthicus sp. nov.; Reduviidae: Emesini) is described from Kartchner Caverns, a limestone cavern in Kartchner Caverns State Park near Benson, Arizona, USA. Cavernicolous emesines are recorded from caves in many parts of the world and are distributed across several genera, but are generally uncommon. P. labyrinthicus shows no obvious troglomorphy but ecological evidence suggests it is, at minimum, a cave-limited troglophile. The species seems to be low-humidity intolerant, due to its occurrence in a cave within a desert region, effectively confines the population to the cave, and the species may thus actually be troglobitic by default. Arachnophily in emesines is more common, including in Phasmatocoris Breddin, but has been previously documented in only a single cavernicolous species, Bagauda cavernicola Paiva, reported from India, Malaysia and Sri Lanka. However, unlike P. labyrinthicus, B. cavernicola is apparently not morphologically adapted for its arachnophilous association. P. labyrinthicus is the only known troglophilic emesine that is also a morphologically adapted and behaviorally functional arachnophile. The only other known cavernicolous Phasmatocoris (P. xavieri Gil-Santana, Alves, Barrett and Costa) is recorded from a sandstone cave in Brazil. P. xavieri exhibits morphological features indicative of a potentially arachnophilous habit, but its ecology has not been studied. Adults of P. labyrinthicus share characteristics with the species Phasmatocoris praecellens Bergroth, P. minor McAtee and Malloch, P. xavieri, P. spectrum Breddin, and P. rapax McAtee and Malloch. Phasmatocoris is primarily a Neotropical genus and the discovery of P. labyrinthicus represents a significant range extension for the genus, being the first Nearctic species identified, with its geographically nearest relative an undescribed species from Mazatlan, Mexico, over 1,000 km to the south.

An investigation for potential extensions of the Karaca Cavern using geophysical methods

It is extremely important for regional tourism to determine the possible extensions of Karaca Cavern, one of the most important tourism destinations of the Gumushane province in Northeast Turkey. Cavities in karstic areas have been frequently revealed using geophysical surveys. This study tried to ascertain the spatial distribution and extension of the limestone cavern system using these techniques. In pursuit of this goal, ground-penetrating radar (GPR), electrical resistivity tomography and seismic tomography methods were performed close to the Karaca Cavern. Appropriate sites for geophysical measurement were selected within the investigation area. The GPR measurements were collected with 100 MHz centre frequency unshielded antennas on 15 profiles over the investigation area of 5,000 m2. Furthermore, both electrical resistivity and seismic tomography data were acquired along with one profile on the site. All data sets were processed and interpreted to visualize the cave as well as the shallow subsurface structure of the site. As a result, it was found that a variety of hyperbolic reflections of different depths and sizes on the radargrams as well as low velocity and high resistivity areas with respect host rock observed in the seismic and resistivity tomography sections may indicate possible extensions of the Karaca Cavern. It has been suggested that locations of anomalies pinpointed using these methods could be opened at the sites. If these places are drilled, the cavern may be enlarged and its importance may increase in terms of tourism.

Induction of Active Invagination of Plasma Membranes by Helicobacter pylori Cytotoxin, VacA, in Cultured Gastric Cells. An Immunoelectron Microscopic Study.

VacA cytotoxin secreted by Helicobacter pylori causes cytoplasmic vacuolation in gastric epithelial cells. To elucidate whether VacA directly affects the cell surface, changes in the membrane structure after VacA treatment were examined in a human gastric epithelial cell culture (AZ−521) at an ultrastructural level. When the time−course changes in the localization of VacA were analyzed by immunoelectron microscopy in AZ−521 cells that had been exposed to VacA, VacA was detected predominantly on the plasma membrane at an early stage of the exposure, and later in endocytotic vesicles and/or tubulo−vesicles. Five to 24hr after exposure, the VacA was distributed in a limestone cavern like−structure, which was formed by elongated surfaces of plasma membranes, as shown by scanning electron microscopy. Therefore, the binding of VacA to the plasma membrane and the subsequent internalization into the enlarged cavern like−plasma membranes may be involved in the induction of vacuolation of gastric epithelial cells by VacA.

Root Mats in Ground Water: A Fauna-Rich Cave Habitat

An unusually rich cave fauna of 41 species is reported from a 20-m stretch of a shallow groundwater stream in Western Australia. Epigean waters do not occur upstream of the cave and, downstream, cave waters emerge at the surface after flowing about 100 m through a system of limestone caverns and collapses. Most of the aquatic cavernicoles collected from the cave stream, therefore, appear to be confined to the subterranean realm. Potential food sources for the aquatic fauna of the cave were investigated. Inputs of dissolved organic matter, surface debris, cadavers, and guano into the cave stream were lacking or too small to provide sufficient energy for the abundant aquatic cavernicoles. Aquatic root mats were shown to be the only substantial source of food available. They belong to the native tree Eucalyptus gomphocephala and consist of fine, highly branched, feeder rootlets growing in mycorrhizal association with fungi. Most of the animals, both in terms of density and species number, also occur in the submerged root mats. At least some of the aquatic cavernicoles graze directly on the living rootlets, some feed on root mat detritus, and others are predatory. We propose that tree roots provide an important source of energy for subterranean fauna in shallow groundwaters both in Australia and elsewhere.

Geochemistry of submarine warm springs in the limestone cavern of Grotta Azzurra, Capo Palinuro, Italy: evidence for mixing-zone dolomitisation

Subtidal springs in and around the submarine limestone cavern of Grotta Azzurra, at Capo Palinuro, Italy, discharge fluids which are warm (< 25°C), mildly acidic, depleted in Cl −, Na + and Mg 2+, and enriched in Si, alkalinity, Ca 2+, Sr 2+, Mn, NH 4 +, PO 4 3− and H 2S, relative to surrounding seawater. The compositions of the warm fluid samples collected in and around the cave define mixing lines which suggest dilution of a single thermal fluid ( T ≥ 23°C) by cool overlying seawater ( T= 17–17.6°C). The chemical data suggest that the proposed thermal fluid contains two components, one derived from seawater (< 90%) and the other from low-salinity groundwater (> 10%). Excess Si, alkalinity, Ca 2+, Sr 2+ and Mn relative to seawater are likely derived from the groundwater component or dissolution/hydrothermal alteration of the host rocks. Magnesium has been removed from the seawater component in exchange for Ca 2+, due to dolomitisation of the limestone and/or hydrothermal alteration reactions. Saturation-state calculations suggest that the vented fluids are near saturation with respect to calcite and supersaturated with respect to dolomite. This and the presence of dolomite in the host rocks and cave-floor sediments suggest that “mixing-zone” dolomitisation of the limestones is occurring, perhaps kinetically assisted by elevated temperature and/or bacterial mediation in the reducing subseafloor zone. One possible “end-member” condition is considered for the thermal fluid — zero-Mg — which suggests an end-member temperature of 50.5°C and a fluid composition derived from ∼ 38% seawater and ∼ 62% groundwater. The heat source for the circulating fluids is uncertain, but may involve warm underlying igneous rocks or heating via the geothermal gradient. A continuous in-situ record of vent-fluid temperature, salinity, pH and O 2 concentration collected within the cavern is consistent with our interpretation of the fluid origin, and suggests that tidal forcing affects circulation and venting of the warm fluids.

Assessment of minestone for the infilling of abandoned limestone caverns in the West Midlands : Scott, R A; Sleeman, W; Rainbow, A K M Proc of the Symposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes, Durham, 10–14 Sept 1984 P47.1–47.17. Publ London: NCB, 1984

Assessment of minestone for the infilling of abandoned limestone caverns in the West Midlands : Scott, R A; Sleeman, W; Rainbow, A K M Proc of the Symposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes, Durham, 10–14 Sept 1984 P47.1–47.17. Publ London: NCB, 1984

Nitrobacterin Mammoth Cave

Mammoth Cave, a large limestone cavern in Mammoth Cave National Park in the Central Kentucky karst, was first mined for saltpetre in 1808 and was a major source of nitrates used in the manufacture of gunpowder during the War of 1812. The mechanism of saltpetre formation is unknown, although hypotheses encompassing both biotic and abiotic functions have been suggested. Present studies were conducted in various saltpetre caves using species specific fluorescent antibodies in order to determine if the chemoautotroph, Nitrobacter, were present. Population densities and species distribution of Nitrobacter were studied in relation to chemical and physical parameters for over 200 sediment samples from Mammoth Cave. Both the isolation and immunofluorescence data indicate that Nitrobacter are present in relatively high population densities in Mammoth Cave sediments, and that such bacteria are common among saltpetre caves in the southeastern United States. Immunofluorescence data further indicates that N. agilis dominates the Nitrobacter population in Mammoth Cave. The possibility that Nitrobacter is the etiological agent for saltpetre formation is suggested.

Analysis of Scallop Patterns by Simulation under Controlled Conditions

Working with plaster of paris in an experimental flume, the authors have simulated the formation of scallop patterns, an intriguing feature of eroded limestone, under controlled conditions of velocity and viscosity. Analysis of the resulting scallop lengths as a frequency distribution has shown that certain of the statistical parameters are well correlated with the hydrodynamic conditions. Length is inversely related to velocity and directly to viscosity. These results are similar to those found by Curl (1966) in a theoretical dimensional analysis of the simpler flute problem. Work in limestone caverns has confirmed that these results apply to scallops generated on limestone. Certain lithologic effects have been noted, however, and these are believed to be correlated with the physical structure of the material.

Concepts of Equilibrium, Grade and Uniformity as Applied to Slopes

Ford, D. C. 1965 The origin of limestone caverns: a model from the Central Mendip Hills, England. Nat. speleo. Soc. Bull. 27: 27. Sweeting, M. M. 1950 Erosion cycles and limestone caverns in the Ingleborough district. Geogr. J. 115: 63. Waltham, A. C. (1970a) Shale units in the Great Scar limestone of the Southern Askrigg Block. Proc. Yorks geol. Soc. (in press) 1970b Speleogenesis of the caves of Leck Fell, in Limestone and caves of North-west England; Ed. M. M. Sweeting. David and Charles (in press).

DETECTION OF SOLUTION CHANNELS IN LIMESTONE BY ELECTRICAL RESISTIVITY METHOD*

AbstractThe results of geophysical surveys carried out in the Kopili Hydel Project site in the United North Cachar and Mikir Hills district, Assam, to locate and trace underground caverns in limestone are presented. Electrical resistivity observations over known limestone caverns showed significant anomalies (high resistivity). In the course of the systematic electrical resistivity survey conducted at the eastern fringe of the Umrong basin to study the competency of the proposed reservoir, a number of indications of possible caverns in limestone were obtained and a few of them have been verified by drilling. An analysis of the electrical resistivity data also suggests that the deep seated caverns are aligned along an axis trending NNW‐SSE, which may represent a zone of weakness– presumably a fault–that has influenced the formation of the caverns in preferred direction. Drilling over a few of the geophysical indications have corroborated the presence of a fault along the eastern fringe of the Umrong basin.

Calcite Precipitates at the Soles of Temperate Glaciers

AROUND Mt Castleguard, Banff National Park in the Rocky Mountains of Canada, we have found extensive deposits of a calcite precipitate which show striking morphological characteristics and which undoubtedly have formed at the soles of glaciers. They are analogous to travertine crusts in limestone caverns, but show stronger orientation and other different features.

Infrasonic Resonances in Natural Underground Cavities

Several examples of acoustic resonance in the frequency range from 0.001 to 1.0 Hz have been observed in limestone caverns. In some cases, the cavern geometry is simple enough for direct application of the Helmholtz resonator theory, and good agreement is found. Three experiments are described. Spectral analysis indicates that subacoustic resonance is responsible for numerous reports of periodically fluctuating or reversing cavern winds, and that appropriate wind measurements can provide new information about chambers not accessible to exploration.