Karst: un concepto muy diverso

La gran diversidad intrínseca del karst y la variedad de campos científicos desde los que ha sido estudiado este medio ha generado un espectacular aumento de su conocimiento. Ese avance ha venido acompañado también de nuevas incógnitas y nuevos planteamientos. El presente trabajo trata de recoger una pequeña muestra de esa amplia diversidad, asociada a un elevado grado de especialización, que de forma integrada permite completar el puzzle del karst. Inicialmente, se presenta una revisión sintética del concepto de karst, del proceso de karstificación y de las morfologías asociadas al mismo. Seguidamente, y planteado a partir de una serie de interrogantes, se muestran algunos aspectos y curiosidades relacionadas con el karst. Las características microclimáticas subterráneas, el karst no tradicional o los depósitos y mineralizaciones asociados al karst, son algunos de los temas que se incluyen en este trabajo y que puede interesar a los docentes que imparten docencia sobre el karst

Brazilian cave heritage under siege

info:eu-repo/semantics/publishe

New peculiar cave ceiling forms from Carlsbad Caverns (New Mexico): the zenithal ceiling tubeholes

During a trip to the Hall of the White Giant, Carlsbad Caverns (NM, USA) cigar-shaped vertically upward developing holes were observed on the ceiling at different heights of the passages. They have a circular cross-section with diameters of 1 to some centimetres and taper out towards their upper end. Their walls are smooth and their bottom edges sharp, while their length can reach several decimetres. Sometimes gypsum can be found inside. They often occur randomly distributed in groups and their development is not necessarily controlled by fractures or other bedrock structures. We name these peculiar karren-like cave microforms “zenithal ceiling tube-holes” because of their origin by H2S environment corrosion processes and their vertical (zenithal) upward growth in ceilings. A comparison is made between zenithal ceiling tube-holes and other karstic or non karstic similar forms such as bellholes, oxidation vents, snailholes, Korrosionskolke (mixture-solution hollows) or pockets, röhrenkarren, light-oriented photokarren, borings of (often marine) organisms and negative stalactites. Zenithal ceiling tube-holes are created by the corrosive effect of sulphuric acid. H2S(g) dissolves in water giving rise to widespread sulphuric acid corrosion. When H2S bubbles are trapped underneath overhanging surfaces or ceilings and water level rises steadily the corrosive effect is concentrated vertically upwards, drilling vertical holes that can also completely pass overhanging rock ledges

Utilización de códigos QR para la evaluación continua en alumnos/as de Psicología Básica (prácticas)

El presente Proyecto pretende mejorar la calidad docente a través de la inserción de nuevas herramientas TIC (formularios google y códigos QR) que permitan al alumno la evaluación continua de su propio aprendizaje

Microclimate processes characterization of the giant Geode of Pulpí (Almería, Spain): technical criteria for conservation

The giant Geode of Pulpí (Almería, Spain) can be considered as one of the most significant recent mineralogical discoveries in terms of geological heritage. Any tourist exploitation of this mining environment should be sustainable, and the first step is to determine the feasibility of opening the interior of the geode to visitors. To achieve this objective it was necessary to characterize the variation of physical parameters of the air and rock (gypsum crystals) during monitored visits, similar to the hypothetical visits that would occur if the geode were opened to the public. The main environmental impact of a continuous presence of people inside the geode is condensation on the surface of the gypsum crystals as a result of increased temperature and water vapor caused by respiration. The phenomenon of condensation on the gypsum crystals begins to occur with visits of two or three people for longer than 10 min. Condensation on the crystal surface brought about by this human presence could lead to the corrosion of the crystals. The total recovery time required after a visit of this type to resume the initial natural thermal and humidity conditions was 27 h. The results obtained from the environmental monitoring of the geode suggest that it is not feasible to allow visits inside it because of the mechanical impact of the visitors on the crystals and of the risk of condensation of water vapor. Copyright © 2005 Royal Meteorological Society

Large-scale visit experience in caves in natural conditions, la Cueva del Agua de Iznalloz (Granada)

The regime of visits in the Cueva del Agua is strictily restricted what allows to carry out an environmental control of the cave under natural conditions before the realization of any tourist activity inside. An underground laboratory has settled in the cave with continuous control of a set of environmental variables. In the framework of this environmental control we have been carried out several controlled visits with the purpose to determine the affection that massive visits could have on the stability of the cave. The initial knowledge of the cave environment variations in natural conditions has been used to identify possible anthropic affections, so that they could be separated from the variations directly related to natural changes; especially the relative influence of the external climatology, the thermal modification caused by the visit and the later thermal recovery of the cave after the visi

About the origin of the groundwater salinity in the delta of the andarax river (Almería)

The salinity proceses affecting of groundwaters from the delta of the Andarax river are very complex. A group of processes occur in relation with the leaching of saline materials of marine origen and with the seawater intrusion. Simultaneously there are ionic exchange processes between these salinizated waters and the sediment

About the origin of the groundwater salinity in the delta of the andarax river (Almería)

The salinity proceses affecting of groundwaters from the delta of the Andarax river are very complex. A group of processes occur in relation with the leaching of saline materials of marine origen and with the seawater intrusion. Simultaneously there are ionic exchange processes between these salinizated waters and the sediment

Air pressure influence in the drip of a stalactite. The case of the Cueva del Agua (Iznalloz, Granada)

The time series analysis of a drip rate and electric conductivity of a stalactite in Cueva del Agua (Granada) during five hydrological years, has allowed to characterize several themes of the vadose infiltration. The increase of air pressure variations is one of the main factors of drip rate non-linearity (cave air pressure oscillation of 10 ± 3.7 mbar induce a drip rate variation of 0.5 ± 0.2 mm/h). This air pressure increase provoke a rise of air phase thickness inside drip to the detriment of the water phase, decreasing so the stalactite drip rat

Organic matter of fossil origin in the amberine speleothems from El Soplao Cave (Cantabria, Northern Spain)

Unusual amberine-coloured speleothems were recently found in El Soplao Cave (Cantabria, Spain). Chromophore elements such as Fe, Mn, Cd, Co or Ti were not present in significant quantities. Rather, our data show that their colour comes from leachates of fossilized organic material hosted in the carbonaceous Urgonian facies of the host rock. These leachates are related to the Cretaceous amber deposit that has been recently discovered in the vicinity of El Soplao Cave. The presence of humic and fulvic acids of fossil origin were confirmed by IR and Raman spectroscopic analysis of the carbonaceous strata and the speleothems. In addition, the mineralogy of the amberine speleothems was studied. Alternating bands made of calcite and aragonite reveal that periods of humidity and aridity occurred within the cave during the speleothem genesis