Motivated by ongoing efforts to understand the nature and the energy potential of geothermal resources, we devise a coupled numerical model (hydrological, thermal, mechanical), which may help in the characterization and monitoring of hydrothermal systems through computational experiments. Hydrothermal areas in volcanic regions arise from a unique combination of geological and hydrological featu...

Hydrothermal sulfide chimneys located along the global system of oceanic spreading centers are habitats for microbial life during active venting. Hydrothermally extinct, or inactive, sulfide deposits also host microbial communities at globally distributed sites. The main goal of this study is to describe Fe transformation pathways, through precipitation and oxidation-reduction (redox) reactions...

The field work, backscattered electron images and detailed microanalyses of three generations tourmaline from the Namacotche LCT pegmatites allows de distinction between compositional magmatic hydrothermal tourmalines. generation 1 occurs in outer intermediate zone pegmatite. It consists zoned crystals with an oscillatory inner core foitite schorl, schorl Fe-rich fluor-elbaite rim. Unzoned occu...

Hydrothermal processes have been suggested to explain a number of observations for Mars, including D/H ratios of water extracted from Martian meteorites, as a means for removing CO2 from the Martian atmosphere and sequestering it in the crust as carbonates, and as a possible origin for iron oxide-rich spectral units on the floors of some rifted basins (chasmata). There are numerous examples of ...

the komshecheh barite-fluorite deposit is the product of epigenetic hydrothermal mineralizationin dolomitized limestone of middle triassic age. the deposit is structurally and lithologically controlled andoccurs predominantly as bedded stratabound replacement sheets, although the veins and solution-collapsebreccias constitute important modes of occurrence. brecciation, dolomitization, silicific...

Regional differences in clay mineralogy are found in British Lower Palaeozoic slate belts formed during Caledonian terrane amalgamation. Extensional basins in Wales, the northern Lake District and the Isle of Man are characterized by a greater diversity of species in clay mineral assemblages. Slates that evolved in these basins contain both the Kand Na-rich products of the 2:1 dioctahedral reac...

We present isotopic analysis of helium in hydrothermal fluids from the Manus back-arc basin, collected during the French-Japanese Manusflux and Manaute cruises in 1995 and 2000, respectively. The helium isotope composition of the fluids is comparable to that measured elsewhere in similar subduction environments, with 3He/4He values (7.4 to 7.9 Ra) slightly lower than typical MORB values, except...