introduction the shahrestanak mn deposit is located in southern qom province, 12 km southwest of the city of kahak. based on geological-structural divisions of iran, the deposit belongs to central volcanic belt or urumieh-dokhtar zone. the venarch deposit is one the most important known manganese deposits in iran. the sharestanak and venarch deposits are spatially and temporally related to each...

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...

polycrystalline mfi zeolite membranes were prepared on α-alumina tubular support by hydrothermal treatments at 413 k. the synthesized zeolite membranes were characterized by xrd, sem and single gas permeation. the influence of hydrothermal treatment steps and the calcination time on the zeolite layer formation were investigated. mfi zeolite membrane prepared by four subsequent hydrothermal trea...

Hydrothermal vent fluids are highly enriched in iron (Fe) compared to ambient seawater, and organic ligands may play a role in facilitating the transport of some hydrothermal Fe into the open ocean. This is important since Fe is a limiting micronutrient for primary production in large parts of the world’s surface ocean. We have investigated the concentration and speciation of Fe in several vent...

Taal Volcano is one of the most active volcanoes in the Philippines. The magnetotelluric 3D forward analyses indicate the existence of a large high resistivity anomaly (∼100 Ω·m) with a volume of at least 3 km×3 km×3 km, which is capped by a conductive layer (∼10 Ω·m), beneath the Main Crater. This high resistivity anomaly is hypothesized to be a large hydrothermal reservoir, consisting of the ...

Marine siliceous rocks are widely distributed in the central orogenic belt (COB) of China and have a close connection to the geological evolution and metallogenesis. They display periodic distributions from Mesoproterozoic to Jurassic with positive peaks in the Mesoproterozoic, Cambrian--Ordovician, and Carboniferous--Permian and their deposition is enhanced by the tensional geological settings...

The spectral and spatial properties of the advanced spaceborne thermal emission and reflection radiometer (ASTER) data can be used in detailed lithological and hydrothermal alteration mapping related to copper and gold mineralization, particularly the shortwave infrared radiation subsystem where hydrothermal alteration minerals have diagnostic spectral absorption features. This paper reviews th...

We report the synthesis of nanoapatite crystals via a hydrothermal reaction of hydroxyapatite precipitates. The impact of the reaction conditions on the properties of the crystals obtained were evaluated. The hydrothermal reaction that takes place markedly affected the crystallinity, morphology, and size of the nanoapatite crystals formed. High crystallinity and large crystal size were obtained...

Introduction: The Cassini spacecraft detected a gas plume emanating from Saturn’s icy satellite Enceladus [13]. Its composition (91% H2O, 3.2% CO2, 4% N2, and 1.6% CH4) was inferred based on measurements by the Ion and Neutral Mass Spectrometer [2]. Jets from warm (110-160 K) fissures (“sulci”) supply the plume [3], and boiling water in a subsurface reservoir may power the jets [1]. Liquid wate...

Shallow-water hydrothermal systems represent extreme environments with unique biogeochemistry and high biological productivity, at which autotrophic microorganisms use both light and chemical energy for the production of biomass. Microbial communities of these ecosystems are metabolically diverse and possess the capacity to transform a large range of chemical compounds. Yet, little is known abo...