[1] The radiogenic isotopic ratios of Sr, Nd, Hf, and Pb in basaltic lavas associated with major hot spots, such as Hawaii, document the geochemical heterogeneity of their mantle source. What processes created such heterogeneity? For Hawaiian lavas there has been extensive discussion of geochemically enriched source components, but relatively little attention has been given to the origin of dep...

In Alpine glacierised catchments, snowand icemelt are chemically enriched and modified during transit though subglacial hydrological systems by distinct bio-geochemical weathering reactions. The nature and extent of these reactions are dictated by waters source and meltwater routing. This chemical modification of meltwaters has been applied in hydrochemical and hydroglacial studies, based mainl...

[1] Theoretical geochemical modeling has been used to evaluate the formation conditions of amorphous silica during aqueous alteration of typical Martian igneous rocks at 0 C. The models show that some silica can form during low-temperature alteration of mafic to ultramafic rocks over a large range of pH and water/rock ratios. Silica-dominated deposits, like those found at the Columbia Hills in ...

Surface geological and geochemical mapping have been key technical contributors to many gold discoveries over the past 25 years. However, in the last ten years there has been a growing emphasis on using geophysical techniques to compliment them in covered terrains. As the search for gold deposits under covered areas expands, there will be increasing emphasis on integrating the geoscientific dis...

â  using of prediction models is one of the methods of financial performance prediction. financial ratios are employed as predictive variable in prediction models. the main purpose of this study is to compare the incremental information content of accrual and cash ratios for prediction and evaluation of the financial performance of business entities by data mining models. in align with research...

At the south of Bardsir, Kerman province, Iran, southeastern part Urmia-Dokhtar magmatic arc (UDMA), a large number gabbroic intrusions are intruded into Eocene lava flows and pyroclastic rocks with form small stocks dykes. In this paper, geochemical variations, evolutions, origin these investigated. The studied characterized by fine-grained margins resulting from rapid cooling flow differentia...

Although the production of U-series disequilibria during metasomatic and partial-melting processes in Earth’s mantle is well studied, the effects of melting and assimilation processes during ascent and storage of magma in the crust are less well understood. To investigate disequilibria arising via this mechanism, we have conducted U-series measurements on the products of laboratory experiments ...

The Sample Analysis at Mars (SAM) instrument suite of the Mars Science Laboratory (MSL) Curiosity rover is a miniature geochemical laboratory designed to analyze martian atmospheric gases as well as volatiles released by pyrolysis of solid surface materials (Mahaffy et al., 2012). SAM began sampling the martian atmosphere to measure its chemical and isotopic composition shortly after Curiosity ...

The isotopic composition of Pb and the concentrations of.Pb, Ba and Bi were measured in selected ice-core samples from Law Dome, East AntarctIca, to a depth of 1196 m. The range of concentrations found in decontaminated ice was 0.03\.5 pg g I for Pb, 0.96.1pggl for Ba and 0.417 fgg I for Bi , excluding the deepest sample which contained rv I p:}6m of rock dust. The abundances of all four stable...

A multi-component reactive transport model, coupled to an existing thermal, hydraulic and mechanical model is investigated. The model is based on conservation of mass/energy principles for the flow and stress strain equilibrium for the mechanical behaviour. The resultant model is coupled to a geochemical model in order to capture geochemical interactions. Numerically, the Galerkin finite elemen...