Global analyses of 88 families and 284 genera of brachiopods from middle Ashgill, Late Ordovician, to early-middle Rhuddanian, Early Silurian, indicate that 18.6% and 12.5% of families and 51.0% and 41.3% of genera were ...

A new approach is developed to evaluate the rates of crust generation and hence the quantities of incompatible elements processed through the continental crust over the last 4 Ga. This relies more on minor and trace elements, ...

In anoxic environments, microbial fermentation is the first metabolic process in the path of organic matter degradation. Since little is known about carbon isotope fractionation during microbial fermentation, we studied ...

Adsorption of germanium on goethite was studied at 25 °C in batch reactors as a function of pH (1-12), germanium concentration in solution (10-7 to 0.002 M) and solid/solution ratio (1.8-17 g/L). The maximal surface site ...

Hornblende phenocrysts in recent andesites of the Soufrière Hills Volcano display reaction rims of microcrystalline plagioclase, pyroxene, Fe-oxides and interstitial glass, formed by decompression during magma ascent. Mass ...

The metamorphic basement of the Pannonian Basin consists of uplifted highs and deep sub-basins among them. One of the best-known highs is the so-called Szeghalom Dome, which is surrounded by less intensely explored ones. ...

Zircon from lower crustal xenoliths erupted in the Navajo volcanic field was analyzed for U-Pb and Lu-Hf isotopic compositions to characterize the lower crust beneath the Colorado Plateau and to determine whether it was ...

Reactions involving feldspars are of great importance in the environment, influencing geochemical cycles in many ways. Dissolution of feldspars has been widely studied in the laboratory, with attempts being made to reproduce ...

Determining the kinetics of many geologic and engineering processes involving solid/fluid interactions requires a fundamental understanding of the Gibbs free energy dependency of the system. Currently, significant discrepancies ...

We use trace-element concentrations in olivines and glasses from a closed basaltic system to identify the effects of petrologic processes on the trace-element record of that system. The closed basaltic system in question ...