almabulage complex is located in the north of asadabad city, northwestern hamedan province, in sanandaj-sirjan structural zone. the complex includes several types of low-grade metamorphosed rocks with various protoliths as well as two intrusion having different chemical compositions of synogranite and gabbro. the synogranite intrusion rock has perthite and granophyric co-growths textures and au...

Article history: Received 11 July 2012 Accepted 15 January 2013 Available online 7 February 2013 Editorial handling by Peter Birkle Groundwater chemistry and isotope data from 44 public supply wells in the Napa and Sonoma Valleys, California were determined to investigate mixing of relatively shallow groundwater with deeper hydrothermalfluids.Multivariate analyses includingCluster Analyses,Mult...

the ali-abad porphyry copper deposit is located in the central iranian magmatic belt. as a result of subduction magmatism, oligo-miocene leucogranitoid rocks have intruded into conglomerates of lower cretaceous age. due to contact metamorphism the following mineral assemblage has occurred in the altered conglomerate: garnet (andradite-grossular) + epidote+ quartz + calcite + pyrite skarnificati...

In the past few decades, chemosynthetic ecosystems at deep-sea hydrothermal vents have received attention as plausible analogues to the early ecosystems of Earth, as well as to extraterrestrial ecosystems. These ecosystems are sustained by chemical energy obtained from inorganic redox substances (e.g., H2S, CO2, H2, CH4, and O2) in hydrothermal fluids and ambient seawater. The chemical and isot...

We present Os data for axial high-temperature and off-axial low-temperature hydrothermal solutions from the Juan de Fuca Ridge. The high-temperature, H2S-bearing axial fluids have unradiogenic Os isotopes pointing to a nearly complete domination of osmium isotopes from the basalts during hydrothermal circulation. The ridge axis fluids typically do not show large enrichment in osmium concentrati...

Knowledge of metal complexes in natural hydrothermal fluids is fundamental to our understanding of ore formation as well as other processes involving interactions between aqueous solutions and solids such as metamorphism. Our present understanding of the structure of metal complexes in natural hydrothermal fluids is incomplete due to the paucity of solubility and spectroscopic studies on geolog...

[1] Formation of a sulfate-bearing ocean on Jupiter’s satellite Europa by quenched hydrothermal fluids provides a source of metabolic energy for low-temperature sulfatereducing organisms that use dissolved H2 as an electron donor. Inhibition of thermodynamically favorable sulfate reduction in cooled hydrothermal fluids creates the potential for biologic reduction. Both high temperature and redu...

Among the deep-sea hydrothermal vent sites discovered in the past 30 years, Lost City on the Mid-Atlantic Ridge (MAR) is remarkable both for its alkaline fluids derived from mantle rock serpentinization and the spectacular seafloor carbonate chimneys precipitated from these fluids. Despite high concentrations of reduced chemicals in the fluids, this unique example of a serpentinite-hosted hydro...

Chemical and isotope data were obtained for the active gas and noble gas of inclusion fluids in coarse-grained samples of magmatic-hydrothermal and magmatic-steam alunite from well-studied deposits (Marysvale, Utah; Tambo, Chile; Tapajós, Brazil; Cactus, California; Pierina, Peru), most of which are discussed in this Volume. Primary fluid inclusions in the alunite typically are less than 0.2 Am...