volcanic rocks of interest are situated in the middle part of the urumieh-dokhtar magmatic arc (udma). they are parts of a vast magmatic province located in the north of bitlis-zagros suture zone. having a prevailing porphyritic texture, these rocks include phenocrysts of plagioclase, amphibole and biotite in a matrix composed of feldspar, quartz, opaque, glass and microlite and mineralogically...

ered sulfur (30%) and sulfur glass (30%) give a better fit to the spectral features than do other candidate materials. We use chemical equilibrium calculations to model S2O forEarlier, Hapke (1989) proposed a mixture of solid S2O mation by high temperature thermochemical reactions in volcanic gases on Io. The calculations predict formation of 1–6% S2O with SO2 frost, polysulfur oxides (SxO)y , ...

The paper presents two experimental methods for basalt processing by microwaves, and their results. One method employs a single-mode cavity to melt basalt, and to produce a volcanic glass (obsidian). The other method uses an open-end applicator (i.e. a microwave drill [1]) to form holes in basalt rocks. Experimental observations of the basalt interactions with microwaves in these two schemes ar...

In this thesis, the results from a geophysical mapping and coring campaign of Lagoa das Furnas are presented. Specific focus is placed on the origin of a subaqueous volcanic cone mapped in the southern part of the lake. Lagoa das Furnas is a crater lake within the Furnas volcanic centre which is located on the island of São Miguel in the Azores archipelago. The Furnas volcanic centre has a long...

Introduction: Angrites are basaltic meteorites that cooled rapidly early in the evolution of the solar system [1]. They are widely thought to be products of differentiation and partial melting [2-4], though it has been suggested that they condensed from vapor in the solar nebula [5,6]. D’Orbigny (“D’O”) is vesicular and has abundant glass [2,5-7]. This has been interpreted as volcanic and seen ...

Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry. This paper presents S/(3)He ratios of vesicles in mid-ocean ridge (MOR) basalt glass together with the ratios of high-temperature hydrothermal fluids to calculate the sulphur flux of 100 Gmol/y at MOR. The S/(3)He ratios of h...

Nearly a decade ago, Gorter (1) suggested that the Bedout basement high, offshore Western Australia, might represent an impact structure, in view of the site_s well-defined circular Bouguer anomaly and seismic reflection data indicating a possible ring syncline. Recently, Becker et al. (2), as part of the search for the cause or causes of the mass extinction that marks the Permian-Triassic (P-T...

Hydrothermal precipitates associated with active vents in the eastern Manus back-arc basin, Papua New Guinea, are among the most gold rich yet discovered on the modern sea floor. The volcanic rocks associated with this mineralization were investigated to determine if they are sufficiently enriched in gold to account for the gold content of the sulfides by simple leaching and to determine whethe...