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Geoquímica dos preenchimentos sedimentares de grutas: a matéria orgânica na gruta do Caldeirão

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... Situated within the carbonated units of the Middle Jurassic, along with those of the Lower Jurassic, enclosed in a meridian outcropping formation between Condeixa and Tomar, defi ning a specifi c Morpho-structural unit: the limestone Massif of Sicó-Alvaiázere (Cruz 1988;Galopim de Carvalho 1996). ...
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The Upper Morgado shelter is a karst cavity located in the Nabão river valley whose material culture is in many aspects associated to the dolmen world. This shelter was used and reused in a long diachrony (since Neolithic times until the Early Bronze Age). Exchange and /or Interchange is confirmed through the occurrence of some metal artefacts that observed a complete set of relationships with items found travelling through the Portuguese Estremadura and Alentejo, across borders to Almeria and as far France. The upper Morgado shelter fits the purpose of a long-term study where the thesis that the funerary features themselves travelled across borders as ideological exchange. Recent research found several ritual actions regarding the systematic burial of individuals of both sexes and of all ages. Since the primary burial, in an unstructured pit, that with time transforms itself into a Chalcolithic ossuary; further complemented with vestigial nuclei of human bones from the Neolithic. Those ossuaries were posteriorly displaced and containerised in a circular rock structure, with small rock niche-ossuary structures containing a limited number of unstructured bones. All this material culture behaviour results in the complex nature of this site.
In a greenhouse experiment, we evaluated the effects of scrubber sludge on the aggregation and the porosity in various combinations of dredged sediments and topsoil in the presence of sudangrass roots. As expected, the water-stable aggregates increase with increasing percentage of topsoil. For all combinations, scrubber sludge decreased aggregation. The topsoil had a total porosity similar to the sediments at the completion of the study in the absence of scrubber sludge. The total porosity increased with additional quantities of scrubber sludge for all combinations of topsoil and sediments. Transmission (>50 [mu]m), water storage (50 to 0.5 [mu]m), and residual (<0.5 [mu]m) pore volumes differed substantially between the sediments and topsoil, as well as with scrubber sludge treatments. The sediments had a higher water retention difference than the topsoil. The presence of scrubber sludge had little effect on topsoil, but reduced the water storage volumes for the sediments. With scrubber sludge addition, the residual pore volumes remained high for topsoil, but decreased substantially for sediments. For all combinations of topsoil and sediments, scrubber sludge dramatically increased transmission porosity. This increase in transmission pores within the sediments with scrubber sludge additions resulted in a higher rate of saturated flow of water than for the sediments without scrubber sludge. The pore-size distributions were estimated by water-release methods and verified by directly measuring soil pore-size distributions by Hg-intrusion porosimetry.
Soil samples from the Benson site, a former Huron Indian village (1600's) were collected on a 1-m grid at a depth of 15 cm over a portion of the village. The Benson site is located about 90 km northeast of Toronto, Canada.Discriminant analysis statistically distinguishes between groups of cases by the employment of descriminating variables. This mathematical technique made it possible to rank the chemical attributes of soil materials as to their usefulness in discriminating between Huron settlement features such as middens, pits, longhouses, hearths, posts and former pathways. Two discriminant analyses were performed in this study. One utilized all the features of the village and the other analysis did not include the chemical data from soils in the midden or pits. The midden and some pits were exceedingly rich in most elements which overshadowed the amounts found in other features. This tended to complicate the analysis of the data by statistical methods. It was found, however, that soils of the former paths can be separated from those of pits, posts and longhouses on exchangeable-magnesium levels. In addition, organic and inorganic phosphorus levels between the soils of the paths, pits and houses were statistically distinct. Dolomite, exchangeable calcium and potassium levels are statistically different enough to distinguish the soils in paths or walking trails from those of posts.Exchangeable magnesium was the most useful chemical constituent of the soil material analyzed at the Benson site in terms of the number of settlement features that could be distinguished by this information alone. Exchangeable magnesium is followed by: organic phosphorus; dolomite; inorganic phosphorus and calcite; exchangeable calcium, potassium and pH; and organic carbon, in its usefulness in separating Huron settlement features on the basis of chemical attributes of the soils.