Search

The discovery of Movile Cave in 1986, similarly to the discovery of the deep-sea vents 9 years earlier, showed that, when redox interfaces are present in subsurface ecosystems, diverse and abundant biological communities can thrive based primarily on autochthonous food produced in situ by chemosynthesis. Additional caves, partially flooded by sulfidic water have been discovered, i.e. the Frasassi caves in Italy, Ein-Nur Cave and Ayyalon Cave in Israel, Melissotrypa Cave in Greece, Tashan Cave in Iran, caves in the Sharo-Argun Valley in the Caucasus Mountains, etc. All of these are inhabited by numerous endemic cave-adapted organisms present in dense populations sustained by a rich food base generated within the subterranean environment by microorganisms that use atmospheric oxygen to oxidize the reduced chemical compounds present in the water (H2S, NH4+, CH4). Stable isotope data has shown that the biological communities found in sulfidic caves are not dependent on carbon fixation in green plants that use light energy in the process of photosynthesis. Special adaptations have been identified in some of these inhabitants that allow them to cope with the adverse environmental conditions such as toxicity of H2S, hypoxia, and extreme pH values. Symbiotic associations between crustaceans, protozoa, and sulfide oxidizing bacteria were discovered in several sulfidic caves. New species of microorganisms have also been described from these unusual subsurface environments. Unusual microbiomes have recently been discovered in dry caves that contain chemoclines between heavy volcanic gasses dominated by CO2, but also containing H2S and CH4, and atmospheric air that floats on top of the volcanic gas emissions. Unique sulfur mineralization, microbial biofilms containing new species of bacteria that thrive at extremely pH values, symbiotic relationships between bacteria and fungi have been discovered in Sulfur Cave in Romania, Bosoletto Cave in Italy, and Sousaki caves in Greece. The extreme life conditions encountered in these caves are of special interest to astrobiologists using these caves as a model for better understanding conditions that life may be present in on other planets and celestial bodies in our Solar System and beyond.

15 páginas.- 5 figuras.- 85 referencias.- The following are available online at http://www.mdpi.com/2079-6412/10/11/1134/s1 .- This article belongs to the Special Issue Biofilms on Cultural Heritage, The Galapagos Islands (Ecuador) have a unique ecosystem on Earth due to their outstanding biodiversity and geological features. This also extends to their subterranean heritage, such as volcanic caves, with plenty of secondary mineral deposits, including coralloid-type speleothems and moonmilk deposits. In this study, the bacterial communities associated with speleothems from two lava tubes of Santa Cruz Island were investigated. Field emission scanning electron microscopy (FESEM) was carried out for the morphological characterization and detection of microbial features associated with moonmilk and coralloid speleothems from Bellavista and Royal Palm Caves. Microbial cells, especially filamentous bacteria in close association with extracellular polymeric substances (EPS), were abundant in both types of speleothems. Furthermore, reticulated filaments and Actinobacteria-like cells were observed by FESEM. The analysis of 16S rDNA revealed the presence of different bacterial phylotypes, many of them associated with the carbon, nitrogen, iron and sulfur cycles, and some others with pollutants. This study gives insights into subsurface microbial diversity of the Galapagos Islands and further shows the interest of the conservation of these subterranean geoheritage sites used as show caves, This research was funded by the Ecuadorian Ministry of Environment (Project PC-65-14 National Park Galapagos), by the Spanish project MINECO CGL2016-75590-P with European Regional Development Fund and the Portuguese Foundation for Science and Technology (Fundação para a Ciência e a Tecnologia-FCT) under the project UID/Multi/04449/2019 for HERCULES/UE. AMGS was supported by a FPU fellowship of the Spanish Ministry of Education, Culture and Sport (AP2010-2052). AZM was supported by a Marie Curie Intra-European Fellowship of the European Commission’s 7th Framework Programme (PIEF-GA-2012-328689-DECAVE) and a CEECIND/01147/2017 contract from FCT. MLC was supported by a CEECIND/00349/2017 contract from FCT. FG was financially supported by the “HIPATIA” research program of the University of Almeria.

The Galapagos Islands (Ecuador) have a unique ecosystem on Earth due to their outstanding biodiversity and geological features. This also extends to their subterranean heritage, such as volcanic caves, with plenty of secondary mineral deposits, including coralloid-type speleothems and moonmilk deposits. In this study, the bacterial communities associated with speleothems from two lava tubes of Santa Cruz Island were investigated. Field emission scanning electron microscopy (FESEM) was carried out for the morphological characterization and detection of microbial features associated with moonmilk and coralloid speleothems from Bellavista and Royal Palm Caves. Microbial cells, especially filamentous bacteria in close association with extracellular polymeric substances (EPS), were abundant in both types of speleothems. Furthermore, reticulated filaments and Actinobacteria-like cells were observed by FESEM. The analysis of 16S rDNA revealed the presence of different bacterial phylotypes, many of them associated with the carbon, nitrogen, iron and sulfur cycles, and some others with pollutants. This study gives insights into subsurface microbial diversity of the Galapagos Islands and further shows the interest of the conservation of these subterranean geoheritage sites used as show caves. Ministerio del Ambiente de Ecuador (Parque Nacional Galápagos)-PC-65-14 Ministerio de Economía y Competitividad de España (MINECO) y el Fondo Europeo de Desarrollo Regional de la Unión Europea (FEDER)-CGL2016-75590-P Portuguese Foundation for Science and Technology. Fundação para a Ciência e a Tecnologia (FCT)-UID/Multi/04449/2019 HERCULES/UE

Fil: Morante López, Rubén. Universidad Veracruzana; México. Nuestros estudios de los observatorios subterráneos (Morante 1993, 1995, 1996a, 2010; Morante, Garza y Valencia 2018) iniciaron en 1986 y, aunque en ese momento no lo sabíamos, seguíamos la línea de investigación que inició en 1963 Franz Tichy (1980). Sugerimos entonces que fueron instrumentos para determinar posiciones astronómicas, en especial del Sol, que señalaban fechas importantes para la economía de los pueblos mesoamericanos, ya que señalaban la proximidad del tiempo de lluvias, alrededor del solsticio de verano. Propusimos también que sus constructores pudieron haberse inspirado en accidentes naturales, como las cuevas (Morante, 1993). Sin embargo, para el centro de México, adonde registramos los observatorios subterráneos más antiguos, no habíamos encontrado cámaras con un tiro en su bóveda que fuese apropiado para estas observaciones. Sin embargo, en los últimos años investigamos dos casos; algunos de sus resultados se reportan aquí. Our studies about underground observatories (Morante 1993, 1995, 1996a, 2010; Morante, Garza and Valencia 2018) began in 1986. Then, we did not know that in 1963 Franz Tichy (1980) had begun similar studies in this field. As he did, since the beginning, we suggested (Morante, 1989) that those chambers and chimneys were instrum ents used to determine astronomicalpositions, especially of the Sun, in order to point out important economic dates for the economy of Mesoamerican peoples, such as the proximity of rainy season, close to the summer solstice. We also suggested that their constructors may have been inspired by natural accidents, such as caves (Morante 1993). However, for central Mexico, where we studied the oldest underground observatories, we had not found such accidents with appropriate conditions to observe. Recently we investigated two cases; here we present some results.

This contribution aims to analyse depositional and post-depositional processes from two volcanic caves (Baño Nuevo 1 and Cueva de la Vieja) from west-central Patagonia, in order to evaluate if natural and anthropogenic processes recorded therein are representative of basin-scale processes. For this purpose, geomorphological, sedimentological, micromorphological, petrographic, magnetic, paleontological and archaeological data are integrated. Results allow correlating the Baño Nuevo 1 and Cueva de la Vieja sequences, comprising a record of ca. 19,000 years. In the first place, the distinction between endogenous and exogenous detritus input, mainly recorded by the mineralogy and lithotypes, provided environmental data related to landscape stability (i.e., vegetation cover). The latter, in turn, could be interpreted as part of a complex feedback associated with major climatic changes. On the other hand, cave weathering rates observed through vertical variations of the gravel fraction, along with bioactivity recorded by percentages of Total Organic Carbon and micromorphological analysis, provided constraints on temperature and/or humidity, being in agreement with available regional information. Main regional palaeoenvironmental changes observed in the sequences were the deglaciation processes, the Pleistocene-Holocene transition, the Holocene amelioration and the Anthropocene. Although no distinctive variations were observed within Holocene deposits, biological processes mainly resultant of the human occupations could have obliterated such finer scale distinctions. Fil: Ozán, Ivana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: Méndez, César. Centro de Investigación en Ecosistemas de la Patagonia; Chile Fil: Oriolo, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: Orgeira, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: Tripaldi, Alfonsina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: Vásquez, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina

11 páginas.- 7 figuras.- 1 tabla.- 73 referencias.- Supplementary data to this article can be found online a https://doi.org/10.1016/j.scitotenv.2019.134321, Siliceous speleothems frequently reported in volcanic caves have been traditionally interpreted as resulting from basalt weathering combined with the activity of microbial communities. A characteristic feature in lava tubes from Hawaii, Azores and Canary Islands is the occurrence of black jelly-like speleothems. Here we describe the formation process of siliceous black speleothems found in a lava tube from La Palma, Canary Islands, Spain, based on mineralogy, microscopy, light stable isotopes, analytical pyrolysis, NMR spectroscopy and chemometric analyses. The data indicate that the black speleothems are composed of a hydrated gel matrix of amorphous aluminum silicate materials containing charred vegetation and thermally degraded resins from pines or triterpenoids from Erica arborea, characteristic of the overlying laurel forest. This is the first observation of a connection between fire and speleothem chemistry from volcanic caves. We conclude that wildfires and organic matter from the surface area overlying caves may play an important role in the formation of speleothems found in La Palma and demonstrate that siliceous speleothems are potential archives for past fires., A.Z. Miller acknowledges the support from the Marie Curie Intra-European Fellowship of the European Commission seventh Framework Fig. 6. Contour van Krevelen density plots displaying cumulative abundances of pyrolysis compounds identified in Table S2 for: A) Erica arboreabiomass, B) Andosol topsoil, C) Black jelly-like speleothem 1 (BS1), and D) Black jelly-like speleothem 2 (BS2).9A.Z. Miller et al. / Science of the Total Environment 698 (2020) 134321 Programme (grant PIEF-GA-2012-328689) and the CEECIND/01147/2017 contract funded by Fundação para a Ciência e a Tecnologia (Portugal). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and ERDF funds forfi-nancial support. The authors are grateful to the speleologist OctavioFernández (GE Tebexcorade–La Palma) for the assistance during thefield trip and photographic documentation in the lava tubes from LaPalma Island

Recently, the study of mineralogical and geomicrobiological interactions in volcanic caves is gaining relevance, because there are many factors to consider them as Mars analogues for astrobiology and planetary sciences. In addition, sulfuric acid caves have also shown to be an important field of study for the understanding of chemolithoautotrophic metabolic pathways, especially in regard to the biogeochemical cycle of sulfur compounds. Hitherto, sulfur-rich volcanic caves found in Central America were almost unknown to the scientific community. This work presents the mineralogical and microbiological diversity and the potential geomicrobiological links found in active volcanic settings, such as Cueva los Minerales (CMI) and Cueva los Mucolitos (CMU) at Irazú volcano (Costa Rica), and Cueva Hoyo de Koppen (CHK) at El Hoyo volcano (Nicaragua). The volcanic caves at Irazú volcano (Costa Rica) are located in the northwest (NW) foothills of the main crater. These caves became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate in situ active minerogenetic processes. Detailed mineralogical and geochemical analyses were performed to study the speleothems at CMI and CMU. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization was done using Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In noveladdition, measurements of cave environmental parameters, cave drip water, and a compilation of geochemical analyses of the Irazú volcanic lake (located ca. 150 m above the cave level) and fumarole analyses, were conducted between 1991 and 2014. Forty-eight different mineral phases were identified, mostly rare hydrated sulfates of the alunite, halotrichite, copiapite, kieserite and rozenite groups thirteen of which are described here, as cave minerals, for the first time, i.e. aplowite, bieberite, boyleite, dietrichite, ferricopiapite, ferrinatrite, lausenite, lishizhenite, magnesiocopiapite, marinellite, pentahydrite, szomolnokite, and wupatkiite. The presence of other novel cave minerals, such as tolbachite, mercallite, rhomboclase, cyanochroite, and retgersite, is likely, but this was not possible to confirm by the various mineralogical techniques employed in this study. It was determined that uplifting of sulfurous gases, water percolation from the Irazú volcanic lake, and hydrothermal interactions with the volcanic host rock are responsible for such extreme mineralogical diversity. Moreover, acidic (pH < 2) viscous biofilms, known as snottites, were observed hanging from both, walls and ceiling, of the caves at Irazú volcano, in close relation with the presence of sulfate minerals. Knowledge about snottites in volcanic caves is scarce, being biofilms present in carbonated rocks the most studied, e.g. at Frasassi and Acquasanta caves (Italy), and Cueva de Villa Luz and Luna Azufre (Mexico). 16S rRNA techniques (with primers for target Bacteria and Archaea), together with bioinformatics analyses, were used to investigate the snottites from CMU and CMI. The results indicated that both prokaryotic groups in the snottites offer a vast metabolic potential to execute various reactions, including redox reactions. The phylogenetic findings revealed that approximately 65% of the identified taxa corresponded to species related to sulfur-oxidizing metabolic pathways (e.g., Leptospirillum, Mycobacterium, Acidithiobacillus and Acidiphilium), while just 0.04% corresponded to sulfur-reducing species (Desulfosporosinus). Since sulfur-oxidizing microorganisms appeared to be dominant in the acidic snottites, induced-gypsum precipitation by changes in micro environmental conditions, is strongly suggested as the path for biomineralization at the studied caves. 34S isotope signature of sulfur minerals presented negative values (from -16.2 to -3.4 ‰), comparable with data obtained... V zadnjem času postaja proučevanje mineraloških in geomikrobioloških interakcij v vulkanskih jamah vse pomembnejše, saj so številne podvržene podobnim dejavnikom, ki kažejo, da bi lahko bile Marsov analog za astrobiologijo in planetarno znanost. Poleg tega so se tudi žveplene jame izkazale pomembne za razumevanje kemolitoautotrofnih metabolnih poti, zlasti biogeokemijskega cikla žveplovih spojin. Vulkanske jame, bogate z žveplom na območju Srednje Amerike, so znanstveni skupnosti praktično nepoznane. V pričuječem delu proučujemo mineraloško in mikrobiološko raznolikost ter potencialne geomikrobiološke interakcije v aktivnih vulkanskih okoljih, kot so jame Cueva los Minerales (CMI) in Cueva los Mucolitos (CMU) v vulkanu Irazú (Kostarika), ter Cueva Hoyo de Koppen (CHK) v vulkanu El Hoyo (Nikaragva). Jame vulkana Irazú (Kostarika) se nahajajo na severozahodnem vznožju glavnega kraterja. Postale so dostopne po delnem podoru SZ sektorja vulkana Irazú leta 1994, kar je omogočilo raziskati aktivne procese nastajanja mineralov v vulkanskih jamskih okoljih na tem geografskem območju. Opravljene so bile podrobne mineraloške in geokemijske analize jamske sige v CMI in CMU. Mineraloške analize so vključevale rentgensko difrakcijo (XRD) in ramansko spektroskopijo, medtem ko je geokemična karakterizacija vključevala energijsko disperzijsko rentgensko spektroskopijo (EDX) v navezavi z vrstično elektronsko mikroskopijo (SEM). Opravljene so bile meritve okoljskih parametrov v jamah ter analize preniklih voda v jamah, poleg tega pa še analiza zbranih geokemijskih podatkov vulkanskega jezera Irazú (~ 150 m nad nivojem jame) in fumarol za obdobje med letoma 1991 in 2014. Identificirali smo 48 različnih mineralnih faz, večina so redki hidrirani sulfati, aluniti, halotrihiti, kopiapiti, kieseriti in rozeniti trinajst jih je tukaj opisanih prvič kot jamski minerali, tj. aplowit, bieberit, boyleit, dietrichit, ferikopiapit, ferinatrit, lausenit, lishizhenit, magneziokopiapit, marinelit, pentahidrit, szomolnokit in wupatkiit. Prisotnost drugih novih jamskih mineralov, kot so tolbahit, merkalit, rombomklaz, cianohroit in retgersite, je verjetna, vendar tega ni bilo mogoče potrditi z uporabljenimi mineraloškimi tehnikami. Ugotovljeno je bilo, da je vzrok za tako ekstremno mineraloško raznolikost izhajanje žveplenih plinov, pronicanje vode iz vulkanskega jezera Irazú in hidrotermalne interakcije z okoliško vulkansko kamnino. Kisli viskozni biofilmi (pH < 2), znani kot snotiti (mukozni stalaktiti) v vulkanskih jamah vulkana Irazú visijo na stenah in stropih jam in so v tesni povezavi s sulfatnimi minerali. O snotitih v vulkanskih jamah je malo znanega, še največ vemo o tovrstnih biofilmih iz primerov bolj raziskanih podzemnih jam v karbonatnih kamninah in sicer, jamah Frasassi in Acquasanta (Italija), Cueva de Villa Luz ter Luna Azufre (Mehika). Molekularne metode proučevanja 16S rRNA (z oligonukleitidnimi začetniki za Bakterije in Arheje) so bile skupaj z bioinformatskimi analizami uporabljene za proučevanje mukoznih stalaktitov iz CMU in CMI. Rezultati so pokazali, da imata obe prokariontski skupini mikroorganizmov velik metabolični potencial za različne biokemijske reakcije, vključno z oksidoredukcijskimi. Filogenetske analize so pokazale, da približno 65% identificiranih taksonov ustreza vrstam, povezanim z metabolizmom za oksidacijo žvepla (npr. Leptospirillum, Mycobacterium, Acidithiobacillus in Acidiphilium), medtem ko je samo 0,04% taksonov pripadalo vrstam, ki lahko reducirajo žveplo (Desulfosporosinus). Rezultati kažejo, da so v kislih snotitih mikroorganizmi, ki oksidirajo žveplo prevladujoči to pa lahko pomeni, da so za biomineralizacijski proces za izločanje sadre v proučevanih jamah ključne spremembe mikrookoljskih pogojev. 34S izotopske vrednosti so bile za minerale negativne (-16,2 ‰ do -3,4 ‰) in so primerljive z vrednostmi iz drugih žveplenih jam, npr. Frassasi, Cueva de Villa Luz, Lechuguilla in Provalata, kjer so bile dokazane...

La isla de El Hierro tiene 46 yacimientos paleontológicos, la mayoría de los cuales se encuentran en cavidades volcánicas (tubos y simas) desarrolladas en los materiales emitidos durante la actividad volcánica cuaternaria. Otros yacimientos paleontológicos se pueden encontrar en paleoformas litorales, materiales aluviales y acumulaciones escatológicas. Los fósiles más importantes que se encuentran en estos yacimientos son restos de especies de lagartos gigantes y aves, algunos extintos. Siete de estos depósitos se proponen en este trabajo como lugares de interés geológico del Geoparque Mundial de la UNESCO de El Hierro, con base en diferentes criterios de valoración científicos, socio-culturales y socio-económicos. Pero es necesario realizar una carta paleontológica insular en la que se establezcan los límites cartográficos de cada uno de ellos, así como las medidas a implementar para su conservación y puesta en valor The island of El Hierro has 46 paleontological sites, most of which are in volcanic cavities (tubes and chasms) developed in materials emitted during Holocene activity. Other paleontological sites can be found in coastal paleoforms, alluvial materials and scatological accumulations. The most important fossils found in these deposits are the remains of giant lizard species and birds, some of them extinct. Seven of these deposits have been proposed as places of geological interest in the UNESCO Global Geopark of El Hierro, based on different scientific, socio-cultural and socio-economic assessment criteria. But it is necessary to make an insular paleontological chart in which the cartographic limits of each of them are established, as well as the measures to be implemented for their conservation and valorization

La isla de El Hierro tiene 46 yacimientos paleontológicos, la mayoría de los cuales se encuentran en cavidades volcánicas (tubos y simas) desarrolladas en los materiales emitidos durante la actividad volcánica cuaternaria. Otros yacimientos paleontológicos se pueden encontrar en paleoformas litorales, materiales aluviales y acumulaciones escatológicas. Los fósiles más importantes que se encuentran en estos yacimientos son restos de especies de lagartos gigantes y aves, algunos extintos. Siete de estos depósitos se proponen en este trabajo como lugares de interés geológico del Geoparque Mundial de la UNESCO de El Hierro, con base en diferentes criterios de valoración científicos, socio-culturales y socio-económicos. Pero es necesario realizar una carta paleontológica insular en la que se establezcan los límites cartográficos de cada uno de ellos, así como las medidas a implementar para su conservación y puesta en valor, The island of El Hierro has 46 paleontological sites, most of which are in volcanic cavities (tubes and chasms) developed in materials emitted during Holocene activity. Other paleontological sites can be found in coastal paleoforms, alluvial materials and scatological accumulations. The most important fossils found in these deposits are the remains of giant lizard species and birds, some of them extinct. Seven of these deposits have been proposed as places of geological interest in the UNESCO Global Geopark of El Hierro, based on different scientific, socio-cultural and socio-economic assessment criteria. But it is necessary to make an insular paleontological chart in which the cartographic limits of each of them are established, as well as the measures to be implemented for their conservation and valorization

This project was supported by Centro de Investigación en Ciencias Geológicas of Universidad de Costa Rica (830-B7-A00) and the Costa Rican Department of Science and Technology (MICITT) fund FI-160B-14 to Andrés Ulloa Carmiol. The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and Cueva Los Mucolitos, both located in the northwest foothills of the main crater. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization used Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In addition, measurements of environmental parameters in the caves, cave drip water and compilation of geochemical analyses of the Irazú volcanic lake (~150 m above the cave level) and fumarole analyses were conducted between 1991 and 2014. We identified forty-eight different mineral phases, mostly rare hydrated sulfates of the alunite, halotrichite, copiapite, kieserite and rozenite groups, thirteen of which are described here as cave minerals for the first time. This includes the first occurrence in cave environments of aplowite, bieberite, boyleite, dietrichite, ferricopiapite, ferrinatrite, lausenite, lishizhenite, magnesiocopiapite, marinellite, pentahydrite, szomolnokite, and wupatkiite. The presence of other new cave minerals such as tolbachite, mercallite, rhomboclase, cyanochroite, and retgersite, is likely but could not be confirmed by various mineralogical techniques. Uplifting of sulfurous gases, water seepage from the Irazú volcanic lake and hydrothermal interactions with the volcanic host rock are responsible for such extreme mineralogical diversity. These findings make the caves of the Irazú volcano a world-type- reference locality for investigations on the formation and assemblage of sulfate minerals and the biogeochemical cycle of sulfur, with potential implications for Astrobiology and Planetary science. Publisher PDF

Se describe por primera vez dos cuevas que se encuentran en el sector NW de la ladera externa del cráter principal del volcán Irazú, denominadas cuevas Los Mucolitos y Los Minerales, respectivamente. Se ubican en la corona del deslizamiento que se generó el 8 de diciembre de 1994. Ambas cuevas están formadas en rocas piroclásticas con intensa alteración hidrotermal y se sugiere que el origen de estas se encuentra asociado a espacios entre bloques en una zona de deslizamiento con superficie escalonada, el cual se propone como un nuevo mecanismo vulcanoespeleogenético. Con base en análisis de difractometría de rayos X y propiedades físicas, se identificaron veintiún minerales diferentes, co- rrespondientes a veinte sulfatos y un elemento nativo. Cinco de estos minerales se reportan por primera vez en cuevas a nivel mundial (aplowita CoSO4•4H2O, boyleíta (Zn, Mg)SO4•4H2O, ferrinatrita Na3Fe(SO4) •3H2O, magnesiocopiapita MgFe4+3(SO4)6(OH)2•20H2O y wupatkiíta (Co,Mg, Ni)Al2(SO4)4•22H2O). En la cueva Los Minerales se encuentran diferentes espeleotemas, siendo los agregados cristalinos tipo corteza los más comunes; también se observaron estalactitas, estalagmitas y geiseritas. En ambas cuevas se identifi có la presencia de colonias de bacterias extremófi las (mucolitos). Se proponen cuatro mecanismos principales para explicar la formación de los minerales, que corresponden a: desgasifi cación, solubilización, alteración y deshidratación. Asimismo, se sugiere que la actividad biogénica también podría infl uenciar en la precipitación de algunos de esos minerales. Two caves located on the NW sector of the main crater of Irazú volcano are described for the fi rst time. The caves, called Mucolitos and Minerales, are located at the base of the landslide t on December 8th, 1994, and are found in pyroclastic rocks with intense hydrothermal alteration. We suggest that both caves are associated with spaces between blocks in block slide with stepped surface and this mechanism is proposed as new vulcanospeleological mechanism. We collected twenty samples which were analyzed based on x-ray diffractometry studies and their physical properties. Twenty one differents minerals corresponding to twenty sulfates and one native element were identifi ed. Five of these minerals are reported for the fi rst time in worldwide caves (aplowite CoSO4•4H2O, boyleite (Zn, Mg) SO4•4H2O, ferrinatrite Na3Fe(SO4)3•3H2O, magnesiocopiapite MgFe(+3)4 (SO4)6(OH)2•20H2O and wupatkiitea (Co,Mg,Ni)Al2(SO4)4•22H2O). The cave presents different speleothemes, the crust is the most common one, but also stalactites, stalagmites and geysermites are present. In both caves, the presence of snottites formations (extremophile bacteria colonies) was identifi ed. We propose four principals mineralogenic mechanisms for the formation of these minerals, which correspond to degassing, solubilization alteration and dehydratation. The infl uence of biogenic activity in the precipitation of some minerals is also suggested.

III Congresso Nacional de Espeleologia e I Encontro Internacional de Vulcanospeleologia das Ilhas Atlânticas. Angra do Heroísmo, Açores, Portugal, 30 de Setembro - 4 de Outubro de 1992. Em 1991, no 6th “International Symposium on Volcanospeleology", apresentámos um estudo sobre a distribuição das grutas e algares dos Açores. No presente trabalho apresenta-se uma lista revista e actualizada das grutas e algares da ilha Terceira, sendo igualmente apresentadas seis novas topografias de tubos de lava desta ilha. São igualmente fornecidas informações sobre a localização, comprimento, altitude e fauna de cada gruta. Duas das grutas pertencem ao complexo Pau Velho (Gruta do Caldeira e Branca Opala) estando localizadas na corrente de Java do Pau Velho (I 761). As outras quatro grutas estão localizadas em partes mais antigas da ilha. O comprimento conhecido de cada um dos tubos de lava estudados é o seguinte: Caldeira: 148 m; Branca Opala: 99 m; Coelho: 171,5 m; Achada: 169,8 m; Mercês II: 65 m; Madre de Deus: 244,8 m. Com estas seis novas topografias a ilha Terceira fica com 14 tubos de lava completamente mapeados, o que representa 45% do seu património conhecido. ABSTRACT: In 1991 we presented a paper in the 6lh International Symposium on Volcanospeleology about the distribution of volcanic caves and pits from the Azores. In the present paper we present a complete and updated list of the lava tubes and pits from Terceira and also six new maps and descriptions of lava tubes from this island. Data on the location, length, elevation and fauna of each cave are also given. Two of the lava tubes belong to the Pau Velho complex of caves (Gruta do Caldeira and Branca Opala) being located in the Pau Velho lava flow (1761). The other four lava tubes are located in older parts of the island. The known length of each of the six studied caves are the following: Caldeira= 148 m; Branca Opala= 99 m; Coelho= 171,5 m; Achada= 169,8 m; Mercês II= 65 m; Madre de Deus= 244,8 m. With these new six maps the Terceira has now 14 lava tubes mapped (45% of the known occurring lava tubes).

Copyright © 1993 Sociedade Afonso Chaves. Em 1989 Ogawa publicou um estudo com a listagem e distribuição das grutas e algures dos Açores. O incremento que se deu nos últimos anos na descoberta e estudo de novos tubos de lava e algares nos Açores justifica que se faça agora uma actualização dessa listagem. Ogawa listou 33 grutas e 7 algares sendo estes números agora de 101 e 27, respectivamente. A estas juntam-se ainda seis (6) grutas de erosão marinha e dezasseis (16) outras cavidades subterrâneas. Neste trabalho faz-se uma listagem dos tubos de lava, algures vulcânicos, grutas de erosão marinha e outras cavidades de acordo com a sua distribuição pelas nove ilhas do arquipélago: Corvo (1;-;-;-), Flores (-;-;-;-;), Faial (3;1; -;-;), Pico (28;8; -;-), Graciosa (18;2;-;-), São Jorge (7;5;-;-), Terceira (29;8;4;9), São Miguel (15;3;-;6) e Santa Maria ( -;-;2;1). São fornecidas informações sobre a localização, espeleometria, altitude e ocorrência de fauna para cada gruta e algar. Apresentam-se igualmente uma cuna narrativa da espeleologia Açoreana e alguns comentários sobre a preservação das grutas dos Açores. ABSTRACT: In 1989, Ogawa published an account of the distribution of caves and pits from the Azores. Further work along the last years justifies an updating of the information. Ogawa listed 33 caves and 7 pits; now these numbers are 101 and 27. There are also additional six (6) littoral caves and 'sixteen (16) other type of cavities. In this paper the lava tubes, volcanic pits, littoral caves and other caves are listed according to their occurrence in the islands of the archipelago: Corvo (1;-;-;-), Flores (-;-; -;;), Faial (3; 1; -;-;), Pico (28;8;-;-), Graciosa (18;2;-;-), São Jorge (7;5;-;-), Terceira (29;8;4;9); São Miguel (15;3;-;6) and Santa Maria (-;-;2;1). Some data about the location, speleometric measures, elevation and occurrence of fauna for each cave and pit are also given. A short narrative of Azorean speleology and some information for the preservation of the caves are also provided.

6th International Symposium on Vulcanospeleology. Hilo, Hawaii, August 1991. In 1989 Ogawa published an account of the distribution of volcanic caves and pits from the Azores. Further work in the last few yeas justifies an updating of the information. Ogawa listed 33 caves and 7 pits; now these numbers are 88 and 24. In this paper the caves and pits are listed according to their occurrence in the islands of the archipelago: Corvo (1;0), Flores (0;0), Faial (3;1), Pico (28;8), Graciosa 16;1), São Jorge (7;5), Terceira (20;6), São Miguel (10;3) and Santa Maria (3;0). Some data on the location, length, elevation, and fauna of each cave and pit are also given. During recent speleological expeditions by Os Montanheiros to the islands of Faial, Pico, Graciosa, São Jorge, Terceira, São Miguel, and Santa Maria over 10,000 meters of lava tubes and 400 meters of pits were surveyed and a total of 17 new maps are presented in this work. The longest lava tube, Torres Cave (Pico), is 3,350 meters long, 15 meters high and 22 meters wide. The biggest pit, Algar do Montoso (São Jorge), is 137,5 meters deep. Presently 75% of the known caves have less than 300 meters. Some caves really belong to à single longitudinal lava tube broken into different sections. We also present some comments on-the more re1evant characteristics of each of the main caves and the distribution of lava tubes, pits, and related lava flows in each island. A short narrative of Azorean geology and some information for the preservation of the caves as well as some comments on the relict hypogeum fauna are also provided.