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The present note is an updated inventory of all known cave minerals as March 2011. After including the new minerals described since the last edition of the Cave Minerals of the World book (1997) and made the necessary corrections to incorporate all discreditations, redefinitions, or revalidation proposed by the Commission on New Minerals, Nomenclatures and Classification (CNMNC) of the International Mineralogical Association (IMA), we summed up 319 cave minerals, many of these only known from caves. Some of the minerals building up speleothems are powerful tracers of changes in Quaternary climate, other minerals are useful for reconstructing landscape evolution, or allow discriminating between various speleogenetic pathways. Thus, it is expected that the search for new cave minerals will continue and even more attention will be given to those species that carries information that allow for addressing different problems in various earth sciences fields. In view of the exponential increase of cave minerals over the past 50 years, cave mineralogy conceivably has the potential to grow in the future, especially considering the new advances in analytical facilities.

Poiano is the largest karst spring of the Emilia Romagna region (northern Italy). It drains an aquifer of unique properties composed of anhydrite with halite lenses at depth and gypsum at the surface (both with high NaCl content). Hydrogeological research has been undertaken using automatically recorded hourly data on temperature, electrical conductivity, and water level. Water feeding the Poiano spring is restricted within the gypsum/anhydrite outcrop between the Lucola, Sologno and Secchia rivers. Karstification in the Upper Secchia Valley only concerns the gypsum rocks mainly present along the border and in the shallower parts of the sulfate outcrop and does not appear to occur at depth. Data strongly support the hypothesis that the salt content in the spring water derives from active halokinetic movements. For the first time, the fundamental hydrogeological importance of the anhydrite part inside the sulfate rocks is demonstrated. If gypsum prevails over anhydrite the karst drainage network can extend deep into the rocks following a network of fractures and fissures. Instead, if in the deep parts of the aquifer anhydrite prevails over gypsum, the karst evolution cannot take place at depth and the structure of the underground drainage paths only follows near-surface paths in gypsum.

The caves of Naica (Chihuahua, Mexico) are perhaps the most famous mine caves of the world due to the presence of gigantic gypsum crystals. Nevertheless, very little research has been carried out on these crystals until now. An international multidisciplinary investigation started in 2006 with the aim not only to define the genesis and the age of the Naica gypsum crystals, but also to focus other important scientific aspects of these caves and to ensure a complete documentation and knowledge of these natural wonders which will not be accessible anymore in a few couple of years. The preliminary results of this, still in progress, research allow to date the giant crystals and to define the boundary conditions and the mechanisms which induced their development. For the first time pollens have been extracted from gypsum crystals and their analyses evidenced that some 35 Ky BP the Naica climate was cooler and more humid than today.

Three hypogenic caves within the Naica mine of Mexico (Cueva de los Cristales — CLC, Ojo de la Reina — OR, and Cueva de las Velas — CLV) host spectacular gypsum crystals up to 11 m in length. These caves are close to another shallow cave of the area (Cueva de las Espadas — CLE), with which they cover a 160 m-deep vertical section of the local drainage basin. Similar to other hypogenic caves, all these caves lack a direct connection with the land surface and should be unrelated with climate. A record of multi-technique fluid inclusion data and pollen spectra from cave and mine gypsum indicates surprisingly that climatic changes occurring at Naica could have controlled fluid composition in these caves, and hence crystal growth. Microthermometry and LA-ICP-Mass Spectrometry of fluid inclusions indicate that the shallow, chemically peculiar, saline fluid (up to 7.7 eq. wt.%NaCl) of CLE could have formed from evaporation, during a dry and hot climatic period. The fluid of the deep caves was instead of low salinity (∼ 3.5 eq. wt.% NaCl) and chemically homogeneous, and was poorly affected by evaporation. We propose that mixing of these two fluids, generated at different depths of the Naica drainage basin, determined the stable supersaturation conditions for the gigantic gypsum crystals to grow. Fluid mixing was controlled by the hydraulic communication between CLE and the other deep caves, and must have taken place during cycles of warm-dry and fresh-wet climatic periods, which are known to have occurred in the region. Pollen grains from a 35 ka-old gypsum crystal of CLC corresponds to a fairly homogenous catchment basin made of a mixed broadleaf wet forest, which suggests precipitation during a fresh-wet climatic period and confirms our interpretation of the fluid inclusion data. The unusual combination of geological and geochemical factors of Naica suggests that other hypogenic caves found elsewhere may not host similar crystals. However, this work shows that fluid inclusions and pollen spectra represent a useful tool for cave studies in general, and if used in future studies might be essential to unravel the mechanisms of hypogenic deposition.

The present work deals with the results of long-term micro-erosion measurements in the most important gypsum cave of Spain, the Cueva del Agua (Sorbas, Almeria, SE Spain). Nineteen MEM stations were positioned in 1992 in a wide range of morphological and environmental settings (gypsum floors and walls, carbonate speleothems, dry conduits and vadose passages) inside and outside the cave, on gypsum and carbonate bedrocks and exposed to variable degree of humidity, different air flow and hydrodynamic conditions. Four different sets of stations have been investigated: (1) the main cave entrance (Las Vinicas spring); (2) the main river passage; (3) the abandoned Laboratory tunnel; and (4) the external gypsum surface. Data over a period of about 18 years are available. The average lowering rates vary from 0.014 to 0.016 mm yr− 1 near the main entrance and in the Laboratory tunnel, to 0.022 mm − 1 on gypsum floors and 0.028 mm yr− 1 on carbonate flowstones. The denudation data from the external gypsum stations are quite regular with a rate of 0.170 mm yr− 1. The observations allowed the collecting of important information concerning the feeding of the karst aquifer not only by infiltrating rainwater, but under present climate conditions also by water condensation of moist air flow. This contribution to the overall karst processes in the Cueva del Agua basin represents over 20% of the total chemical dissolution of the karst area and more than 50% of the speleogenetically removed gypsum in the cave system, thus representing all but a secondary role in speleogenesis. Condensation–corrosion is most active along the medium walls, being slower at the roof and almost absent close to the floor. This creates typical corrosion morphologies such as cupola, while gypsum flowers develop where evaporation dominates. This approach also shows quantitatively the morphological implications of condensation–corrosion processes in gypsum karst systems in arid zones, responsible for an average surface lowering of 0.047 mm yr− 1, while mechanical erosion produces a lowering of 0.123 mm yr− 1.

This article highlights the relationship between speleothems growing inside gypsum caves and the particular climate that existed during their development. Speleothems in gypsum caves normally consist of calcium carbonate (calcite) or calcium sulphate (gypsum) and the abundance of such deposits greatly differs from zone to zone. Observations carried out over the last 20 years in gypsum caves subjected to very different climates (Italy, Spain, New Mexico, northern Russia, Cuba, Argentina) highlight wide variation in their cave deposits. In arid or semi-arid climates, the speleothems are mainly composed of gypsum, whilst in temperate, humid or tropical regions, carbonate formations are largely predominant. In polar zones no speleothems develop. These mineralogical details could be useful paleoclimatic indicators of climate change. The interpretation proposed is based on the fact that in gypsum karst the kind of speleothems deposited is determined by competition between the two principal mechanisms that cause precipitation of calcite and gypsum. These mechanisms are completely different: calcite speleothem evolution is mainly controlled by CO2 diffusion, while gypsum deposits develop mostly due to evaporation. Therefore, the prevalence of one kind of speleothem over the other, and the relationship between the solution–precipitation processes of calcite and gypsum, may provide evidence of a specific paleoclimate. Additionally, other non-common deposits in gypsum caves like moonmilk, cave rafts and dolomite speleothems can be used as markers for the prevalence of long, dry periods in humid areas, seasonal changes in climate, or rainfall trends in some gypsum areas. Moreover, the dating of gypsum speleothems could contribute paleoclimatic data relating to dry periods when calcite speleothems are not deposited. In contrast, the dating of calcite speleothems in gypsum caves could identify former wet periods in arid zones.

The caves of Naica (Chihuahua, Mexico) are perhaps the most famous mine caves of the world due to the presence of gigantic gypsum crystals. Nevertheless, very little research has been carried out on this karst area until now. A multidisciplinary investigation started in 2006 with the aim not only to define the genesis and the age of the Naica gypsum crystals, but also on other scientific aspects of these caves. This paper describes a completely new type of gypsum speleothem: the “sails”, observed only inside the Cueva de las Velas, one of the caves of the Naica system. This speleothem consists of extremely thin, elongated skeleton crystals that have grown epitaxially only on the tips of the gypsum crystals pointing upward. The genesis of sails is strictly related to the environmental conditions set up inside the cave just after the artificial lowering of the groundwater by mine dewatering (less than 20 yr ago). In a few years sail speleothems will disappear entirely and therefore this study is fundamental to preserve at least the memory of them.

2 páginas.-- 2 figuras, Coralloid-type speleothems were found in Ana Heva lava tube from Easter Island (Chile). The ceiling of the lava tube presents light to dark brown speleothems with globular coral-like shape. To appraise their internal structure and composition, optical microscopy (OM) of cross-sections, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS) and X-Ray micro-computed tomography ( CT) were performed. The latter is a non-destructive method (NDM), performed to assess physical and compositional heterogeneities of the coralloids. The internal structure of these speleothems comprises a succession of thin layers, ranging from white to brown, with vitreous to resinous luster (Fig. 1A). According to their color and texture, four major layers are easily distinguishable, from the surface to their inner part: a superficial dark brown to black coating, with approximately 0.1 mm thick (L1); a 0.1-1 mm thick semi-transparent grayish layer (L2); a 0.1-1 mm thick white layer (L3), and a heterogeneous honey brown layer, with 1-5 mm thick and shades ranging from yellowish to honey brown (L4). FESEM-EDS microanalyses performed on the internal layers of longitudinally cut coralloid samples (Fig. 1B) showed systematic differences in chemical composition of the different color inner layers. In general, they contain variable proportions of Si, Mg and Ca (Fig. 1C-G). According to a previous study [1], the thin dark brown to black coating of the coralloid surfaces is probably derived from the weathering of the overlying volcanic rock and microbial activity [1]. The semi-transparent grayish layer (L2) is composed of low crystalline silica (opal-A), whereas the whitish layers (L3) are calcium carbonate (calcite). In contrast, the honey-brown layers (L4) present an unusual composition characterized by high levels of Mg, corresponding to an amorphous Mg hydrate silicate. Significant content of organic carbon was also found in these layers [1]. The CT study allowed us to confirm the existence of internal zoning in the studied coralloids (Fig. 2), and between them and the basaltic substrate. The brighter domains in the reconstructed images (Fig. 2D,E) correspond to the vacuolar basaltic. The other opaque domains, comprising thin spheroidal precipitates or dispersed spots within the coralloids (Fig. 2F-I), are calcium rich phases. According to mineralogical data and FESEM-EDS analysis, the inner/older spots correspond to apatite and the outer/more recent spots correspond to calcite. In contrast, the Si, Mg and C enriched domains are more transparent to X-ray radiation, combining at least two main phases (siliceous and magnesium silicate compounds). The proposed methodology was considered adequate for studying coralloid samples, by combining a NDM (μCT) with other microanalytical techniques. Investigations of speleothems using the potentialities of μCT provide general morphological and compositional information, suggesting the best approach for selecting and sectioning the samples. The FESEM-EDS provides characteristic information on the morphological, mineral and chemical composition., The authors acknowledge FCT for PEst-OE/CTE/UI0098/2011, AZM (SFRH/BPD/63836/2009) grant, and Spanish Ministry of Science and Innovation (Project CGL2011-2569) and CSIC 210230E125.

Kenya is one of the few countries in which karst cavities are scarce with respect to volcanic ones, which are widespread throughout the whole country. The great variability in lava composition allowed the evolution of very different cavities, some of which are amongst the largest lava tubes of the world. As normal for such a kind of cave, the hosted speleothems and cave minerals are scarce but important from the minerogenetic point of view. Anyway up to present no specific mineralogical research have been carried out therein. During the 8th International Symposium on Volcanospeleology, held in Nairobi in February 1998, some of the most important volcanic caves of Kenya have been visited and their speleothems and/or chemical deposits sampled: most of them were related to thick guano deposits once present inside these cavities. Speleothems mainly consisted of opal or gypsum, while the deposits related to guano often resulted in a mixture of sulphates and phosphates. The analyses confirmed the great variability in the minerogenetic mechanisms active inside the volcanic caves, which consequently allow the evolution of several different minerals even if the total amount of chemical deposit is scarce. Among the observed minerals kogarkoite, phillipsite and hydroxyapophyllite, must be cited because they are new cave minerals not only for the lava tubes of Kenya, but also for the world cave environment. The achieved results are compared with the available random data from previous literature in order to allow an updated overview on the secondary cave minerals of Kenya.

Detailed geomorphological analysis has revealed that subhorizontal gypsum caves in the Northern Apennines (Italy) cut across bedding planes. These cave levels formed during cold periods with stable river beds, and are coeval with fluvial terraces of rivers that flow perpendicular to the strike of bedding in gypsum monoclines. When rivers entrench, renewed cave formation occurs very rapidly, resulting in the formation of a lower level. River aggradation causes cave alluviation and upward dissolution (paragenesis) in passages nearest to the river beds. The U-Th dating of calcite speleothems provides a minimum age for the formation of the cave passage in which they grew, which in turn provides age control on cave levels. The ages of all speleothems coincide with warmer and wetter periods when CO2 availability in the soils covering these gypsum areas was greater. This climate-driven speleogenetic model of epigenic gypsum caves in moderately to rapidly uplifting areas in temperate regions might be generally applicable to karst systems in different geological and climatic conditions.

Research performed in caves has shown the existence of significant effects of gas seeps, especially CO2 and H2S, within subterranean voids. Carbon dioxide causes important corrosive effects and creates characteristic morphologies (e.g., bell-shaped domes, bubble’s trails), but is not involved in the deposition of specific cave minerals. On the other hand, in carbonate environments, hydrogen sulfide when oxidized in the shallow sections of the aquifer generates important corrosion effects and is also responsible for the deposition of specific minerals of which gypsum is the most common. Studies performed in the last few years have shown that H2S seeps in caves are associated with rich and diverse biological communities, consisting of large numbers of endemic species. Stable isotope studies (carbon and nitrogen) have demonstrated that these hypogean ecosystems are entirely based on in situprodu ction of food by chemoautotrophic microorganisms using energy resulting from the oxidation of H2S. Although located only 20 m under the surface, Movile Cave does not receive meteoric waters due to a layer of impermeable clays and loess that covers the Miocene limestone in which the cave is developed. In the Frasassi caves, where certain amounts of meteoric water seep into the limestone, the subterranean ecosystems are still isolated from the surface. As the deep sulfidic waters mix with the oxigenated meteoric waters, sulfuric acid limestone corrosion is accelerated resulting in widespread deposition of gypsum onto the cave walls. Both these caves have raised a lot of interest for biological investigations regarding the chemoautotrophically based ecosystems, demonstrating the possibility of performing such studies in environments that are easily accessible and easy to monitor compared to the deep-sea environments where the first gas seeps were discovered. r 2002 Elsevier Science Ltd. All rights reserved.

The idea that speleothems may be somehow influenced by living organisms is rather old, but specific studies have only started in the last few decades and presently there are only a couple of systematic paper on this topic. The role of microorganisms is perhaps the best investigated even if it is not fully understood, while studies over upper organisms and speleothems in a cavern environment are scarce and details are not always given on the involved genetic mechanisms. The aim of the present paper is to give an updated overview on these topics in order to enhance the interest of the scientific community. In fact the complex biochemical reactions involved in the development of the different cave deposits, though still not well understood, clearly have an interest and an importance far exceeding the simple speleogenetic interest.

The luminescence of calcite speleothems displays an exponential dependence on soil temperature unless there is a dense cover of forest over the cave to dampen it. This relationship is determined primarily by the strength of solar visible and infrared radiation. It is suggested that, as a consequence, the microzonal variations of luminescence often found in speleothems can be used as a proxy index of Solar Insolation. The luminescence solar insolation proxy record of a speleothem from Jewel Cave, South Dakota, USA, was found to display millenial and centennial cycles in the record. It exhibits a rapid increase in solar insolation at 139 :t 5.5 kyrs. This increase precedes that suggested by the Orbital theory by about 10,000 years and is due to superimposition of the most powerful cycle in solar luminosity of 11.5 kyrs, upon the curve of orbital variations. The record from a speleothem in Duhlata Cave, Bulgaria matches that of South Dakota within the limits of dating error, indicating that both of these records (which are 10,000 km apart) measure global solar insolation controls rather than local paleotemperature variations.

11 páginas.-- 8 figuras.-- 1 tabla.-- 33 referencias, Coralloid-type speleothems were recorded on the ceiling of the Ana Heva lava tube in Easter Island (Chile). These speleothems were morphologically, geochemically and mineralogically characterized using a wide variety of microscopy and analytical techniques. They consist dominantly of amorphous Mg silicate and opal-A. Field emission scanning electron microscopy revealed a variety of filamentous and bacillary bacteria on the surface of the Ana Heva coralloid speleothems, including silicified filamentous microorganisms. Among them, intriguing reticulated filaments resemble those filaments documented earlier in limestone caves and lava tubes. The identification of silicified microorganisms on the coralloid speleothems from the Ana Heva lava tube suggests a possible role of these microorganisms in silica deposition. © 2014 Copyright Taylor and Francis Group, LLC., This research was partially financed by Portuguese Funds through FCT- Fundaçao para a Ciencia e a Tecnologia (PEst-OE/CTE/UI0098/2011) and also by the Spanish Ministry of Science and Innovation (Project CGL2011–2569). This work was supported by FCT grant to AZM (SFRH/BPD/63836/2009).

[ES]El reciente descubrimiento de minerales hidratados sobre la superficie de Marte sugiere la presencia de importantes cantidades de agua líquida durante algunas etapas de su historia geológica. A raíz de este hallazgo, los estudios sobre minerales hidratados en ambientes terrestres como potenciales análogos marcianos han adquirido gran relevancia. En el presente trabajo se han estudiado las características mineralógicas y geoquímicas de minerales hidratados procedentes de varias cuevas y minas españolas y de la región minera de Iglesias-Carbonia (Cerdeña, Italia) mediante técnicas espectroscópicas implicadas en misiones de exploración marciana presentes y futuras, con el fin de evaluar su potencial para la detección de este tipo de minerales. Por un lado, se ha utilizado la espectroscopia Raman, que formará parte de la carga científica de la misión ExoMars de la Agencia Espacial Europea. Por otro lado, la espectroscopia de IR, otra de las técnicas involucradas en esta misión de la ESA, así como la espectroscopia LIBS y la combinación de difracción-fluorescencia de rayos X (DRX-FRX), ambas a bordo de la misión MSL de la NASA. Estas técnicas han permitido identificar sulfatos (yeso, epsomita, jarosita y glaucocerinita), silicatos (hemimorfita) y carbonatos (hidrocincita e hidromagnesita), todos ellos minerales hidratados y algunos de los cuales también han sido descritos en Marte. Por otro lado, se han abordado los procesos de formación de estos minerales y las potenciales analogías con la mineralogénesis en Marte. Del conjunto de técnicas empleadas, la combinación Raman-LIBS se perfila como la opción más eficiente para la detección de minerales hidratados en condiciones marcianas., [EN] The recent discovery of hydrated sulfates on the Martian surface suggests that widespread wet conditions were present during its early geological history. Upon this discovery, a growing interest has emerged in the study of this group of minerals from terrestrial environments as potential Martian analogs. Here, we evaluate the potential of various analytical techniques involved in current and future mission to Mars for detecting hydrated minerals from caves and mines of Spain and the mining district of Iglesias-Carbonia (Sardinia, Italy). Minerals were analyzed by Raman spectroscopy, which will be included in the payload of the ESA’s 2018 ExoMars mission. On the other hand, IR spectroscopy, also included in the ExoMars mission, as well as LIBS spectroscopy and a combined XRD-XRF analyzer, both onboard the Curiosity rover of NASA’s MSL mission, were utilized. Hydrated sulfates (gypsum, epsomite, jarosite and glaucocerinite), silicates (hemimorphite) and carbonates (hydrozincite and hydromagnesite) were characterized. Most of these minerals have also been detected on the Martian surface. The mechanisms involved in the genesis of these minerals and the potential analogies with the minerogenesis on Mars are discussed. The Raman-LIBS combination appears to be the most powerful tool for detecting hydrated minerals in Martian conditions. This technology will probably be considered to be onboard of further planetary missions

In the past few years the systematic study of caves intercepted by mine workings in southwest Sardinia has permitted us to observe morphologies due to rare speleogenetic and minerogenetic processes related to ancient hydrothermal activity. These relic morphologies are slowly being overprinted by recent speleogenetic processes that tend to obscure the hypogene origin of these caves. A combined geomorphological and mineralogical investigation has permitted a fairly detailed reconstruction of the various phases of evolution of these caves. Cave formation had already started in Cambrian times, but culminated in the Carboniferous, when most of the large voids still accessible today were formed. A key role in carbonate dissolution was played by sulphuric acid formed by the oxidation of the polymetallic ores present in the rocks since the Cambrian. During the Quaternary a variety of minerals formed inside the caves: calcite and aragonite, that yielded sequences of palaeo-environmental interest, and also barite, phosgenite, hydrozincite, hemimorphite and many others. These minerals are in part due to a phreatic thermal hypogenic cave forming phase, and in part to later epigene overprinting in an oxidizing environment rich in polymetallic ores. Massive gypsum deposits, elsewhere typical of this kind of caves, are entirely absent due to dissolution during both the phreatic cave formation and the later epigenic stage. Copyright © 2013 John Wiley & Sons, Ltd.

Unusual orange ochre crusts were recently discovered in Crovassa Ricchi in Argento Cave (San Giovanni Mine, SW Sardinia). These speleothems appear covering the cave walls on hydrothermal calcite spars as well as filling widened spaces between calcite crystals. Planar crusts display geometrical forms following the boundaries between the calcite spars. EDX-SEM microanalyses reveal that these deposits comprise substances of Fe, Mn, Pb, Zn and O that occur as solid inclusions in pits on the surface of altered calcite microcrystals. Micro-Raman spectroscopy analyses suggest the presence of calcite and ferromanganese oxides with a low degree of crystallinity. The genetic mechanism proposed for these speleothems describes an initial stage of precipitation of euhedral calcite crystals from warm water under subaqueous conditions. The crystal surfaces were eroded and corroded by colder aggressive water that smoothed the surfaces of the crystals and slightly widened the spaces between calcite spars. Metal-rich mud coming from alteration of bedrock and ore bodies filled the cave, also penetrating along the spaces between the calcite spars. When the water table fell below the cave level, part of the sediments was eroded but the cave walls remained covered with metal-rich clayey sediments. Under aerobic conditions, metals - which were reduced in previous stages - oxidized to oxides, lowering the pH and thus the crystal surface and the calcite planes between the spars were corroded. Subsequently, the polymetallic crusts became harder through evaporation within the cave, "fossilizing" the products of this process within the planes between spars. Finally, the exposed calcite surfaces continued to be altered due to CO2 diffusion into condensation water, while the boundaries between crystals were preserved against corrosion thanks to the crust coating. As a result, the external crystal edges protrude by several centimeters from the current cave wall, while the crystal surfaces are depressed, giving rise to calcite "ghosts". © 2013 Elsevier B.V. All rights reserved.

The classification scheme of Hill and Forti, as used in the second edition of Cave Minerals of the World. is presented as a "practical" solution to the classification of cave minerals and speleothems. Classification and naming of cave minerals is by crystal class and follows nomenclature approved by the International Mineralogical Association. Classification of speleothems is based on morphology and whatever is known about origin, with division of speleothems into types, subtypes, and varieties. It is proposed that new speleothem types, subtypes, and names be approved by a UIS Commission of cave mineralogists.

During a fi eld trip in November 2007 at San Pedro de Atacama (Chile) several centimetre- scale white rims and blisters were observed on the salt crust fl oor in the famous Valle de la Luna (moon valley). Th ese curious features are composed entirely of pure white salt and have been encountered in a limited area of about 15,000 m 2 . A total of 35 of these small structures, named here "salt rims" and "salt blisters", have been located and measured. Th eir average plan dimensions are 6.5 x 5.5 cm for a mean height of 3.6 cm. Almost 60% of these structures have an opening on top (salt rims), sometimes on their fl anks, typically smaller than their diameters. Th e biggest features always have an opening, being the closed structures, named blisters, normally less than 3 cm in diameter. A tube-like opening continuing underground for at least a decimetre, mostly deeper than 20 cm, is clearly visible in the inside of the salt rims. Th e rims perfectly match the edges of these holes. In some cases salt crystals grow on the inner walls of the rims forming curving fi laments. Th e salt blisters and rims are very similar to homonymous (sam-name) speleothems and form by condensation-evaporation processes after very sporadic rainy episodes. Rainfall (average annual rain- fall is < 20 mm), occurs very rarely and enables infi ltration of salty water through openings in the salt crusts. Th is water is conveyed underneath the impervious salt crust presumably in a network of inter- connected fi ssures and underground cavities containing airborne fi

In the morning of February 15th 2005, during excavation works in an underground gypsum quarry at Moncalvo (Monferrato area, Asti, Northern Italy), a water-bearing fracture was intercepted at level 134 m a.s.l. During the night a large amount of water (approximately 60,000 m3) and mud invaded the quarry tunnels reaching a height of 139 m a.s.l. the morning of the day after. Meanwhile a large sinkhole (20 m wide and 10 m deep) formed on the surface. Hydrogeological surveys were immediately carried out to follow the quickly evolving situation, while speleological and geomorphological fieldwork was made possible only seven months later. Two important caves were discovered both showing clear evidence of a hypogenic origin with sculpted morphologies due to slowly flowing water under pressure. The sinkhole formed by the collapse of one of the main chambers of the biggest of these caves, when buoyant support provided by the water started to decrease due to lowering of the virtual water table. The recharge of this karst system is from below and only very minor quantities of infiltration water come from the above lying surface, as has also been confirmed by hydrochemical analysis. This hypogene karst is completely invisible at the surface and develops entirely underground showing no relation whatsoever with the surface. Its presence is therefore extremely difficult to reveal and such types of karst can thus make up extremely dangerous situations. This is the first example of hypogene gypsum cave related to ascending waters in Italy.

Roberto Delfrate,1 Massimo Bricchi,1 Paolo Forti,1 Claude Franceschi2 1Surgery Unit, Figlie Di San Camillo Hospital, Cremona, Italy; 2Vascular Exploration Service, St Joseph Hospital, Paris, France Background: Anastomotic leak is a major complication of colorectal surgery. Among the causes of dehiscence, anastomotic ischemia seems to be fundamental and consequently so is the evaluation of the parietal flow. We proposed a new application of infrared flowmeter for the evaluation of the parietal flow at the stumps after colon resection. Objective: The aim of this study is to assess the feasibility of using an intraoperative intestinal wall flowmeter to assess arterial capillary flow in order to avoid the execution of anastomoses in poorly vascularized segments of bowel, and consequently to reduce the risk of anastomotic leakage.Methods: Retrospective analysis of two groups of patients with different methods of evaluation of colon resection stump vascularization. Ninety-two consecutive patients (Group A) underwent surgical colorectal resection for cancer. In this group, we used a pulse-oximetry sensor to assess the parietal flow: once the magnitude of the colon resection was established according to surgical and oncological criteria, the exact location of the resection was adjusted according to the parietal flowmetry curve. This method was compared with 139 consecutive colorectal resections (Group B) in which vascularization was assessed by checking the pulsatility of the mesenteric arteries, macroscopic wall resection stump appearance, and bleeding of the wall stump. The main outcome measure was the reduction in anastomotic dehiscence.Results: In Group A no anastomotic leakage occurred (0/92). Conversely, in Group B six anastomotic leaks occurred (6/139). The statistical analysis of the two groups thanks to the Fisher's exact test shows that P

V Savdski Arabiji je bilo raziskanih in izmerjenih vec velikih vulkanskih jam v razlicnih poljih lave. Ena najvecjih je Ghar Al Hibashi na polju lave Harrat Buqum-Nawasif. To je v glavnem raven rov (400 m dolg in 15 m sirok), dostopen skozi majhno brezno, ki se odpira v stranskem rovu. Jama je dolgo služila za skrivalisce netopirjem, hijenam, volkovom in lisicam. Zaradi tega je dno jame, deloma iz debelih plasti nesprijetega peska, prekrito s stevilnimi kostmi in koproliti ter razmeroma velikimi kupi gvana. Nekateri so se bili vneli, zaradi cesar so deloma zgorele tudi na njih ležece kosti. Edine prave kapnike predstavlja nekaj majhnih, rumenih in prosojnih stalaktitov. Tekom treh odprav 2003 je bilo iz jame vzetih nekaj sekundarnih kemicnih odkladnin za mineraloske preiskave. Kljub majhnemu stevilu vzorcev je bilo do sedaj zaznanih vsaj 19 razlicnih mineralov, najvec takih, ki so povezani z biogeno mineralizacijo kosti in gvana. Trije od teh, pyrocoproite, pyrophosphite in arnhemite, so izredno redke organske spojine, izkljucno vezane na goreci gvano. Do danes so bili ti minerali znani le iz nekaj jam v Afriki. Zahvaljujoc tem odkritjem ni jama Hibashi le najpomembnejsa vulkanska jama v Savdski Arabiji, ampak tudi tamkajsnje dalec najbogatejse mineralosko nahajalisce. Zato te raziskave, ki se zdalec niso koncane, potrjujejo novejse domneve, da so v jamskem okolju prav vulkanske jame najprimernejse za razvoj razlicnih mineralogenih mehanizmov. Several large lava tubes have been explored and mapped in different lava fields around the Saudi Arabia. One of the largest is Ghar Al Hibashi, located in the Harrat Buqum-Nawasif lava field. It mainly consists of a huge rectilinear gallery (over 400 m long and 15 m wide) the access to which is through a small vertical pit reaching a side corridor. The cave was long used as a shelter for bats, hyenas, wolves and foxes. Therefore the entire cave floor, consisting of locally thick uncemented sand, is scattered with a great amount of bones and coprolites, while some rather large guano deposits are also found. Some of these guano deposits caught fire, which partially burnt the bones overlaying them as well. The only true speleothems consist of a few small yellow translucent stalactites. During three expeditions in 2003, a few samples of secondary chemical deposits were collected inside this lava tube to be analysed from the mineralogical point of view. Despite the scarcity of these samples, at least 19 different minerals have already been detected, most of which are related to the biogenic mineralization of bones and guano deposits. Three of them, pyrocoproite, pyrophosphite and arnhemite are extremely rare organic compounds strictly related to the guano combustion, which have been observed until now only in a few caves in Africa. Thanks to these findings Hibashi lava tube is not only the most important volcanic cave of Saudi Arabia but also by far the richest mineralogical shelter of the country. Therefore this research, which is far from coming to an end, confirms the recently advanced opinion that amongst the different cave environments, volcanic cavities are very favourable for the development of different minerogenetic mechanisms.

[Kruger et al. (2013)][1] use a femtosecond-laser system and fluid inclusions to constrain the formation temperature of gypsum speleothems (crystals) formed within the well-studied cave system of Naica, Mexico. The authors focus on two of the several caves documented in that underground mine

Short description of caves and karsts in gypsum of different parts of the World.

Karst speleothemes can be used as a tool for tectonic and seismic analyses; in particular stalagmites can be treated as records of a natural pendulum. These analyses permit the formulation of new hypotheses regarding the activity induced in the surficial faults by deep tectonic systems, as well as the evaluation of main paleoseismic events and their absolute datation. In the present paper the method for analyzing stalagmites is shortly outlined and the main achieved results are reported.

Received 3 April 2007; Revised 14 May 2007; Accepted 21 May 2007 this goal, the “La Venta” Geographical Association performed a study from 1999 to 2003 (Bernabei et al., 2002; Forti et al., 2003). This paper describes the geomorphic aspects of karst landforms and caves surveyed during the field investigation, which testify to an ancient bathyphreatic regional flow of thermal and meteoric waters, probably similar to that which feeds the present springs (Forti et al., 2004b). STUDY AREAGeographical features The Sierra Madre Oriental crosses the state of Coahuila from N to S, with a series of parallel mountain ridges, which enclose fluvio-lacustrine intermontane flats of different extension. The Cuatro Cienegas plain is one of these flat areas. It extends over an area of about 840 km 2 and is located at 27° N and 102° W, at an altitude of about 700 metres. The high sloping walls of the Sierra Madera, which reach an altitude of 3020 m a.s.l., and the lower Sierra Menchaca, form the northern boundary of the area. The Sierra San Vincente and Sierra La Purisima border the plain on the eastern side. The southwestern boundary is the Sierra La Fragua, whereas the Sierra San Marcos y Pinos divides the Cuatro Cienegas plain into two parts in its southern part (Fig. 1). All these mountains consist mainly of Cretaceous limestone folded into long asymmetric anticlines. Their more steep slopes, usually the southwestern sides, often show vertical or overturned beds. Steep slopes and vertical walls are deeply cut by longitudinal and transverse streams, which together form a typical “trellis” pattern. The northeast-facing slopes, many of which correspond to International Journal of Speleology 36 (2) 83-92 Bologna (Italy) July 2007

The analytical problems of dating gypsum speleothems with the U-series technique are reviewed. Gypsum speleothems are, in general, very low in U content, challenging the limits of detection methods. Various approaches to dissolving gypsum and isolation of actinides from the matrix include ion-pairing dissolution with magnesium salts and using nitric acid. The most precise dating technique is Thermal Ionization Mass Spectrometry (TIMS), combined with Fe(OH)3 scavenging and anionic exchange chromatography. Less satisfactory, but much quicker, is direct retention of actinides from HNO3 by means of TRU resin and MC-ICP-MS detection. We have tested these methods on gypsum speleothems from the Sorbas karst in Spain and from the Naica caves in Mexico.