In the search for aqueous habitats on Mars direct proof of (ancient) flowing water is still lacking, although remote sensing has provided indications of young fluvial systems. To demonstrate that such proof can be given, we examined surface marks on recent terrestrial sand grains by atomic force microscopy (AFM) and applied a quantitative three-dimensional analysis that can numerically distingu...

The porosity of a zone can be estimated either from a single “porosity log” (sonic, density, neutron, or magnetic resonance log) or a combination of porosity logs, in order to correct for variable lithology effects in complex reservoirs. In the carbonates, mineral mixtures are primarily drawn from calcite, dolomite, and quartz (either as sand grains or as chert); anhydrite and gypsum may also o...

We examined the processes of calcite nucleation and crystal growth to determine the dominant mechanism for precipitation of calcite in the presence of dissolved organic carbon (DOC). Our experiments, conducted at 25°C and at a Ca:HCO, molar ratio of 1:2, were performed with and without calcite seeds. Scanning electron micrograph observations showed that the particle size of calcite crystals in ...

Recently, we have reported studies of transport and sorption of heavy metal ions in watersaturated quartz sand columns under relatively fast water flow. In these experiments, clear indications for a fast and strong adsorption of the ions to the sediment could be found. Here we report the findings in a series of other experiments performed under static conditions. In this case, much higher conce...

Studies show that the performance of soil water content monitoring (SWCM) sensors is affected by soil physical and chemical properties. However, the effect of organic matter on SWCM sensor responses remains less understood. Therefore, the objectives of this study are to (i) assess the effect of organic matter on the accuracy and precision of SWCM sensors using a commercially available soil wate...

The objectives of this study were to determine the nature (aeolian vs. alluvial) and origin of sandy sediments in southwestern Iran (Khuzestan province) were collected in two transects across (NW-SE directions) and perpendicular to the Karkheh River, by using grain sized distribution characteristics, and the mineralogy and micro-texture of quartz grains of forty-five surface samples (0-30cm) at...