have continued to use the same analytical system (that is, the same sample preparation and decomposition methods, with atomic absorption spectroscopy as the final determination step) to determine 13 elements in stream and lake sediments collected for the RGS program. In the early 1980s, simultaneous determination of 30 elements or more by inductively coupled plasma emission spectroscopy (ICP-ES...

Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from <1 to >100 m. Geochemical heterogeneity in thin flows may be created by...

Introduction: The early history of the Moon, namely the first ~700 My following its formation, was an era marked by the formation of 43 basins (impact craters >300 km in diameter) [1,2,3]. Basin formation during this period had significant effects on the entire lunar crust; material from depth was excavated and redistributed across the entire surface [4]. The material redistributed by basins ca...

Stimulating in situ microbial communities in oil reservoirs to produce natural gas is a potentially viable strategy for recovering additional fossil fuel resources following traditional recovery operations. Little is known about what geochemical parameters drive microbial population dynamics in biodegraded, methanogenic oil reservoirs. We investigated if microbial community structure was signif...

arsenic is one of the heavy metals and nearly all its compounds, especially organic compounds, are toxic. the wide spectrum of diseases caused by this element has led to evaluation of the toxicity of different arsenic species and identification of the major natural and anthropogenic pollution sources of it in the nature. mining activities are among the main sources of anthropogenic pollution of...

Geophysical and geochemical investigations concerning deformation events of tectonic interest at the underground laboratory of Gran Sasso have been carried out and possible correlations with local seismicity are also investigated. We have planned and realized an automatic multiparametric equipment (water temperature, electrical conductivity, pH, Rn) and from the May 1996 we performs automatic m...

The development of conceptual geochemical models is enhanced by saturation index calculations that can identify the equilibrium state of minerals. Speciation modeling provides saturation indices that indicate reactions thermodynamically possible, minerals dissolving and precipitating in an aquifer system. In the present study, aqueous speciation modeling is carried out for the high fluoride gro...