Methane is an energy-dense fuel but is also a greenhouse gas 25 times more detrimental to the environment than CO2. Methane can be produced abiotically by serpentinization, chemically by Sabatier or Fisher-Tropsh chemistry, or biotically by microbes (Berndt et al., 1996; Horita and Berndt, 1999; Dry, 2002; Wolfe, 1982; Thauer, 1998; Metcalf et al., 2002). Methanogens are anaerobic archaea that ...

[1] Characterizing the hydration state of the forearc mantle wedge yields valuable information on frictional stability at the downdip edge of subduction megathrusts. Simultaneous inversion of Pand S-wave arrival times collected as part of the Costa Rica Seismogenic Zone Experiment yields 1D and 3D Pand S-wave velocity models (VP and VS) for the Nicoya Peninsula segment of the Middle America Tre...

[1] The development of transient thermal stress in suboceanic mantle is investigated on the basis of two-dimensional thermoviscoelastic models incorporating composite rheology appropriate for dry oceanic lithosphere. Thermal stress is shown to be sufficiently high to deeply fracture the coldest part of lithosphere, e.g., to the depth of at least 30 km (and possibly down to 50 km) in 100-Ma-old ...

This study focuses on the use of petrology as a useful tool in construction applications (i.e., concrete). More specifically, this investigates how petrogenetic characteristics ultramafic rocks derived from ophiolite complexes (Veria–Naousa, Gerania) can act key for prediction final behaviour aggregates concrete aggregates. For reason, their petrographic, chemical and mineralogical were examine...

The discovery of a liquid ocean on Saturn's small moon Enceladus and evidence modern hydrothermal activity provide an unexpected new environment in which to expand the search for life. However, as with age moons themselves, any therein remains area debate. Based physical chemical observations from Cassini mission we can apply known mineral dissolution rates, estimated water-rock ratios Enceladu...

The occurrence of rhythmic layering of chromite and host serpentinites in the deformed layered igneous complexes has been noticed in the Nuggihalli schist belt (NSB) in the western Dharwar craton, Karnataka, South India. For this study, the chromitite rock samples were collected from Jambur, Tagadur, Bhakatarhalli, Ranganbetta and Byrapur in the NSB. Petrography and ore microscopic studies on c...

The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydro...

Serpentinization, or the aqueous alteration of ultramafic rocks, results in challenging environments for life in continental sites due to the combination of extremely high pH, low salinity and lack of obvious electron acceptors and carbon sources. Nevertheless, certain Betaproteobacteria have been frequently observed in such environments. Here we describe physiological and genomic features of t...