The surface area of the individual phyllosilicates (clay minerals) in Athabasca oil sands determined from XRD crystallite size measurements was found to be comparable to the bulk surface area measured by ethylene glycol monoethyl ether adsorption. The primary phyllosilicates are kaolin and illite but the large surface area is imparted by varying degrees of smectitic interstratifications in the ...

-The addition of a 10% talc internal standard to North Pacific sediments allows the relative abundances of clay minerals to be determined both accurately and precisely by X-ray powder diffractometry. Linear programming can be used to generate factors for converting talc-normalized peak areas to weight percentages; hence, absolute clay-mineral abundances can be estimated. This procedure minimize...

We tested the use of visible to near-infrared (VNIR) reflectance spectroscopy to characterize the relative abundances of clay minerals in sediments from Lake Towuti, a large tectonic lake in Sulawesi, Indonesia. We measured VNIR spectra of lake and river sediments from Lake Towuti and its catchment to identify clay minerals, fit major VNIR absorption features with a modified Gaussian model to e...

Exact estimates of soil clay (<2 μm) and silt (2-20 μm) contents are crucial as these size fractions impact key soil functions, and as pedotransfer concepts based on clay and silt contents are becoming increasingly abundant. We examined the effect of removing soil organic matter (SOM) by H2O2 before soil dispersion and determination of clay and silt. Soil samples with gradients in SOM were retr...

the present study was carried out in kharkeh research station, kurdestan province, western iran to investigate the effects of the change in land use on the degradation of mol-lisols, their organic carbon content, clay mineralogy and k+ status. the study area was partly under cultivation (for over 40 years) and partly preserved as rangelands. the re-sults revealed that mollisols are the dominant...

Potentially toxic elements (PTEs) including nickel and chromium are often present in soils overlying basalt at concentrations above regulatory guidance values due to the presence of these elements in underlying geology. Oral bioaccessibility testing allows the risk posed by PTEs to human health to be assessed; however, bioaccessibility is controlled by factors including mineralogy, particle siz...

[1] We report results on the effects of porewater pH and transients in porewater flow on the deposition and mobilization of colloid-sized clay particles within unsaturated sand columns. The deposition rates of illite under steady-flow conditions were essentially independent of pH, while the deposition rates of kaolinite nearly doubled as the pH decreased from 7.4 to 4.6. Mobilization of kaolini...