The thermodynamic properties of clay minerals, which control the stability of these minerals in solution, are still a matter of debate in spite of recent advances (Gailhanou et al., submitted). This is especially the case for the minerals that may structurally include trace elements and potential radionuclides such like Ni, Cd, Co, Cr, Mn, Pb, ... The usual methods developed in order to predict...

An enigmatic stepwise increase in oxygen in the late Precambrian is widely considered a prerequisite for the expansion of animal life. Accumulation of oxygen requires organic matter burial in sediments, which is largely controlled by the sheltering or preservational effects of detrital clay minerals in modern marine continental margin depocenters. Here, we show mineralogical and geochemical evi...

Clay minerals may be si<j'nifieant indieatoi's of earth processes. They form throufrh a range which involves at one extreme the action of compressed water vapor at a temperature of several hundred degrees centigrade, and at the other extreme, the action of atmospheric agencies at an ordinary temperature. Not recognized as original products of magmatic crystallization, clay minerals are prima fa...

introduction in remote sensing studies, especially those in which multi-spectral image data are used, (i.e., landsat-7 enhanced thematic mapper), various statistical methods are often applied for image enhancement and feature extraction (reddy, 2008). principal component analysis is a multivariate statistical technique which is frequently used in multidimensional data analysis. this method atte...

Nanocomposites of clay minerals and surfactants are of practical importance in many fields. Beside the use of these systems for pollution removal from waste water, they can also be used as catalysts, to stabilize clay formations while drilling for hydrocarbons, or for improving the strength of polymers. The nanocomposites are obtained through exchange of natural counter ions by ionic surfactant...