Microbiology of a hypersaline oil reservoir located in Central Africa was investigated with molecular and culture methods applied to preserved core samples. Here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16S rRNA gene sequences retrieved from the extracted DNA are phylogenetically related to actual Archaea inhabiting surface evaporitic...

Introduction: Meridiani Planum is a vast plain of approximately horizontally bedded sedimentary rocks composed of mixed and reworked basaltic and evaporitic sands containing secondary, diagenetic minerals [e.g., 1-5]. Because bedding planes are subparallel to topography, investigation of contiguous stratigraphy requires examining exposures in impact craters. Early in the mission (sols 130-317),...

A central loop Transient Electromagnetic TEM Resistivity Survey was conducted at the Geysir high temperature geothermal area as part the project of the author. The area is situated 110 km away from Reykjavik and lies in a shallow valley elongated north-south. Geologically it is surrounded by three volcanic domes made-up of rhyolites, hyloclastites and inter-glacial basaltic lava that obtain hea...

Analytical procedures for U-Pb isotope dilution analyses at the Pará-Iso isotope geology laboratory of the Federal University of Pará (UFPA) are described in detail. The procedures are applied to zircon, titanite, rutile, apatite, columbite-tantalite and whole rock. Reagent preparation and chemical processing are done in clean-room conditions. Samples are dissolved using Teflon microcapsules in...

Compaction bands are narrow planar zones of localized purely compressive (without shear) deformation that form perpendicular to the most compressive principal stress. Such bands have been observed in high porosity rocks in the laboratory and in the field. Because compaction presumably decreases permeability, these bands can act as barriers to flow within reservoirs. Reexamination of the results...

Atmospheric CO2 concentration has increased from 280 ppm during pre-industrial times to 380 ppm today as a result of human input, and this is thought to be causing enhanced global warming and ocean acidification1. Between 2000 and 2005, global CO2 emissions from burning fossil fuels averaged 26.4 Gt CO2 yr−1, at or above the highest rates predicted by the Intergovernmental Panel on Climate Chan...

[1] The Nili Fossae region located on the northwestern quadrant of the Isidis Basin, Mars, displays superb exposures of bedrock outcrops that reveal mineralogy and composition of the crust. Previous work has shown that this region exhibits the largest exposures of olivine-dominated rock units on Mars. Visible-infrared imaging spectrometer data acquired by OMEGA were calibrated to surface reflec...

We present a model of a geothermal system supplied at depth by saturated steam. It is shown that as steam rises from depth to lower pressure regions, liquid forms for pressures greater than 3.1 MPa. Once the pressure reaches 3.1MPa and the steam continues to rise into even lower pressure regions, it becomes superheated. Condensate does not form in the zone where pressures are less than 3.1MPa. ...