Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities ...

Subducted oceanic metabasalts are believed to be a primary source of volatiles for arc magmatism and fluid-induced seismicity. From phase equilibria computed for an average oceanic metabasalt we present a model for subduction zone devolatilization for pressures up to 6 GPa (V180 km). Along high temperature geotherms complete dehydration occurs under forearcs, whereas dehydration does not occur ...

The Ciletuh Mélange Complex in West Java, Indonesia, provides evidence of early Cenozoic subduction. This study aims to investigate the stratigraphic position, geological structure, metamorphic facies, and protoliths rock units. research methods employed mapping, petrology, geochemical analysis. samples collected exhibit different including zeolites, greenschist, epidote amphibolite. Protoliths...

Petrophysical properties of cylindrical core specimens from three boreholes the International Continental Scientific Drilling Program, DSeis project, measured at ambient pressure and room temperature conditions in various laboratories are presented compared with downhole petrophysical data (sonic density). The sixty-six rock constituting metasediments, metabasalts intrusives. Seismic velocities...

jian cu deposit is hosted by surian volcano-sedimentary complex of permo-triassic age on the eastern edge of the sanandaj-sirjan metamorphic zone at a distance of 195 km from shiraz, southwestern iran. the complex consists mainly of metabasalt, chlorite-quartz schist, chlorite-muscovite schist, mica schist and graphite schist. pyrite is the most important sulfide and chalcopyrite is the major c...

New geological, bulk chemical and mineralogical (QEMSCAN and FEG-EPMA) data are presented for albitite-type uranium deposits of the Mount Isa region of Queensland, Australia. Early albitisation of interbedded metabasalt and metasiltstone predated intense deformation along D2 high strain (mylonite) zones. The early sodic alteration paragenetic stage includes albite, riebeckite, aegirine, apatite...

1 REGIONAL GEOLOGY 2 The northern California Coast Ranges are composed the Franciscan Complex, a penetratively 3 sheared set of metasedimentary rocks forming an accretionary prism. The Franciscan complex is 4 subdivided into three broad belts that young to the west: the Eastern, Central and Coastal belts, 5 reflecting the cumulative accretion of oceanic sediments to western North America (McLau...

At the Cascadia margin the Juan de Fuca plate is subducting beneath the North America plate, causing active seismicity within both plates. Earthquakes occur down to a maximum depth of 80 km within the descending oceanic plate and to about 30 km in the overriding continental plate. We use a method of seismic tomography to invert 28,230 P wave arrival times from 2666 local earthquakes that occurr...