-A new chemical mass balance technique has been developed for simultaneous mineralogical quantification and chemical characterization of soil clays. The procedure includes separation of the whole clay (<2 ~tm fraction) into six particle size fractions (<0.02, <0.06, <0.2, 0.02-0.06, 0.06-0.2, and 0.22 um fractions), chemical analysis of the whole clay and each of the six fractions, and fitting ...

The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain) have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals), but also in maintaining the high level of microbial diversity detected in the basin. It has been proven th...

Next-generation planetary exploration rovers will soon be able to travel long distances in a single-communication cycle. This offers an enormous opportunity but also an important challenge: robots will need to do science autonomously and understand collected data in order to make more effective exploration decisions. We have developed a system to obtain spectroscopic measurements on-the-fly, po...

tected, as it were, from another crossing over. This relation is illustrated in the diagram (fig. 7). If crossing over occurs at some point between two pairs of factors a and b indicated on the diagram, the next crossing over point of the chromosome would, if it occurred at all, lie at some distance away, rather than near by. This possibility can be tested in a case where several known points a...

MINERALOGICAL and physical characteristics of natural chromites from Oman ophiolites have been recently investigated using M6ssbauer spectrocopy (MS), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) by Al-Alawi et al. (1996). From the MS analysis together with the SEM data, they derived the chemical formula for specimens collected from two separate chromite deposits named Tawiyah...

The Akinbo Formation comprises a sequence of mostly dark, pale-greenish grey, laminated shale, slightly glauconitic shale, sandy shale with subordinate claystone lenses. Selected subsurface samples of the shaly facies as penetrated by Akinside 1582 well in eastern Dahomey basin. were investigated by sedimentological. mineralogical and geochemical parameters to ascertain the hydrocarbon potentia...

Mantle-derived garnet peridotites are a minor component in many very high-pressure metamorphic terranes that formed during continental subduction and collision. Some of these mantle rocks contain trace amounts of zircon and micrometer-sized inclusions. The constituent minerals exhibit pre- and postsubduction microstructures, including polymorphic transformation and mineral exsolution. Experimen...