Cambrian small shelly fossils from the Çal Tepe Formation, Taurus Mountains, Turkey

Lower and Middle Cambrian carbonate rocks of the Çal Tepe Formation, cropping out in the western Taurus Mountains, yielded a large number of microfossil remains. Small shelly fossils from a single level in the upper Lower Cambrian represent a high diversity biota that could be related to the «Cambrian explosion». Microfossil association from the lower Middle Cambrian sediments of the Çal Tepe Formation is taxonomically very reduced and a dominant taxon is Hadimopanella GEDIK. This sudden change could be attributed to a deepening of the basin during the early Middle Cambrian transgression. [RESUMEN] Los sedimentos carbonatados de la Formación Çal Tepe (Montes Taurus occidentales) que corresponden al techo del Cámbrico Inferior y base del Cámbrico Medio, han proporcionado un gran número de restos paleontológicos. Los más antiguos, atestiguan la existencia de una paleobiota muy diversificada que puede vincularse a la «explosión cámbrica». En tanto que los sedimentos del Cámbrico Medio contienen una asociación de fósiles que se caracteriza por una diversidad muy baja en la cual el elemento dominante es Hadimopanella GEDIK. Este cambio dramático registrado por los fósiles estudiados, puede atribuirse a una profundización de la cuenca que sería coincidente con la transgresión de la base del Cámbrico Medio

Astrobiological field campaign to a volcanosedimentary mars analogue methane producing subsurface protected ecosystem: Imuruk Lake (Alaska)

Viking missions reported adverse conditions for life in Mars surface. High hydrogen signal obtained by Mars orbiters has increased the interest in subsurface prospection as putative protected Mars environment with life potential. Permafrost has attracted considerable interest from an astrobiological point of view due to the recently reported results from the Mars exploration rovers. Considerable studies have been developed on extreme ecosystems and permafrost in particular, to evaluate the possibility of life on Mars and to test specific automated life detection instruments for space missions. The biodiversity of permafrost located on the Bering Land Bridge National Preserve has been studied as an example of subsurface protected niche of astrobiological interest. Different conventional (enrichment and isolation) and molecular ecology techniques (cloning, fluorescence "in situ" probe hybridization, FISH) have been used for isolation and bacterial identificationThe expedition to Imuruk Lake was supported by Centro de Astrobiología-INTA (Spain). The laboratory experimental procedures were supported by Grant AYA 2010–20213 “Desarrollo de Tecnología para la identificación de vida de forma automática” from the Spanish Governmen

Deep subsurface sulfate reduction and methanogenesis in the Iberian Pyrite Belt revealed through geochemistry and molecular biomarkers

© 2013 John Wiley & Sons Ltd.The Iberian Pyrite Belt (IPB, southwest of Spain), the largest known massive sulfide deposit, fuels a rich chemolithotrophic microbial community in the Río Tinto area. However, the geomicrobiology of its deep subsurface is still unexplored. Herein, we report on the geochemistry and prokaryotic diversity in the subsurface (down to a depth of 166 m) of the Iberian Pyritic belt using an array of geochemical and complementary molecular ecology techniques. Using an antibody microarray, we detected polymeric biomarkers (lipoteichoic acids and peptidoglycan) from Gram-positive bacteria throughout the borehole. DNA microarray hybridization confirmed the presence of members of methane oxidizers, sulfate-reducers, metal and sulfur oxidizers, and methanogenic Euryarchaeota. DNA sequences from denitrifying and hydrogenotrophic bacteria were also identified. FISH hybridization revealed live bacterial clusters associated with microniches on mineral surfaces. These results, together with measures of the geochemical parameters in the borehole, allowed us to create a preliminary scheme of the biogeochemical processes that could be operating in the deep subsurface of the Iberian Pyrite Belt, including microbial metabolisms such as sulfate reduction, methanogenesis and anaerobic methane oxidation.The MARTE project (Mars Astrobiology Research and Technology Experiment) was a NASA-CAB joint project funded by the NASA ASTEP program project No. NRA-02-OSS-01 and by the CAB internal budget. The present work was supported by the Subdirección General de Proyectos de Investigación, of the Spanish Ministerio de Economía y Competitividad (MINECO) Grants No. ESP2004-05008, ESP2006-08128, AYA2008-04013, and the European Research Council (ERC) Advanced Grant No. 250350. F. Puente-Sánchez has a JAE-pre fellowship from the Spanish Consejo General de Investigaciones Científicas (CSIC).N

Los microfósiles problemáticos del Cámbrico Inferior de la Sierra de Córdoba: datos preliminares

El ataque químico de materiales procedentes de la Sierra de Córdoba y pertenecientes al Cámbrico Inferior, ha dado lugar a la obtención de microfósiles problemáticos de macroorganismos consistentes, fundamentalmente, en tubos de naturaleza fosfática y moldes internos fosfatizados. En este trabajo se resumen los datos preliminares del estudio taxonómico, bioestratigráfico y paleobiogeográfico de los microfósiles obtenidos. [ABSTRACT] The chemical disolution of Lower Cambrian limestones from Sierra de Córdoba have allowed to obtain small shelly fossils consisting in phospbatic tubes and phosphatized inner moulds of selerites. This work deals with preliminary dates of the taxonomic, biostratigraphic and paleobiogeographic study of the microfossils found

Geology of the Ariadnes Basin, NE Eridania quadrangle, Mars – 1:1Million

<div><p>Here we present a 1:1,000,000 geological map of the Ariadnes basin (31–38° S, 170–179° E) (Mars), which is one of the topographic depressions located between Terra Sirenum and Terra Cimmeria in the Martian highlands. This basin is diverse, both in terms of morphology and mineralogy, and it is a site of major interest to study the chronological boundary between the Noachian and Hesperian periods (∼3.71 Ga). However, a detailed map of the area has not yet been published. The map described in this paper was produced through the analysis of recent images and topographic data that allow the definition of the geologic units with unprecedented detail. We distinguished eight units and diverse tectonic and geomorphic features. We also examined the regional stratigraphy by age determination using crater counting in order to constrain the geological history of the Ariadnes basin. The map provides a basis for which later analyses can build understanding of the regional paleoenvironment.</p></div

Iberian pyrite belt subsurface life (IPBSL), a drilling project of biohydrometallurgical interest

The geomicrobiological characterization of Río Tinto, an extreme acidic environment, has proven the importance of the iron cycle, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals) but also in maintaining the high level of microbial diversity detected in the water column and the sediments. The extreme conditions detected in the Tinto basin are not the product of industrial contamination but the consequence of the presence of an underground bioreactor that obtains its energy from the massive sulfide minerals of the Iberian Pyrite Belt (IPB). To test this hypothesis, a drilling project (IPBSL) to intersect ground waters interacting with the mineral ore is under way, to provide evidence of subsurface microbial activities. A dedicated geophysical characterization of the area selected two drilling sites due to the possible existence of water with high ionic content. Two wells have been drilled in Peña de Hierro, BH11 and BH10, with depths of 340 and 620 meters respectively, with recovery of cores and generation of samples in anaerobic and sterile conditions. The geological analysis of the retrieved cores showed an important alteration of mineral structures associated with the presence of water, with production of expected products from the bacterial oxidation of pyrite. Ion chromatography of water soluble compounds from uncontaminated samples showed the existence of putative electron donors, electron acceptors, as well as variable concentration of metabolic organic acids, which suggest the presence of an active subsurface ecosystem associated to the high sulfidic mineral content of the IPB. Enrichment cultures from selected samples showed evidences of an active iron and sulfur cycle, together with unexpected methanogenic, methanotrophic and acetogenic activities. The geological, geomicrobiological and molecular biology analyses which are under way, should allow the characterization of this ecosystem of biohydrometallurgical interest

Río Tinto:A geochemical and mineralogical terrestrial analogue of Mars

The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain) have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals), but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment) (2003–2006) and IPBSL (Iberian Pyrite Belt Subsurface Life Detection) (2011–2015), were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue