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Cu- and Mn-bearing tourmalines from Brazil and Mozambique were characterised chemically (EMPA and LA-ICP-MS) and by X-ray single-crystal structure refinement. All these samples are rich in Al, Li and F (fluor-elbaite) and contain significant amounts of CuO (up to ~1.8 wt%) and MnO (up to ~3.5 wt%). Structurally investigated samples show a pronounced positive correlation between the <Y-O> distances and the (Li + Mn\(^{2+}\) + Cu + Fe\(^{2+}\)) content (apfu) at this site with R\(^2\) = 0.90. An excellent negative correlation exists between the <Y-O> distances and the Al\(_2\)O\(_3\) content (R\(^2\) = 0.94). The samples at each locality generally show a strong negative correlation between the X-site vacancies and the (MnO + FeO) content. The Mn content in these tourmalines depends on the availability of Mn, on the formation temperature, as well as on stereochemical constraints. Because of a very weak correlation between MnO and CuO we believe that the Cu content in tourmaline is essentially dependent on the availability of Cu and on stereochemical constraints.
The explosive expansion of the population of the Metropolitan Region of Curitiba raised a high increase in the demand for water resources and the uncontrolled settlement poses a large problem for the environment. The greatest menace to the water supply sources of this region is the urban occupation (invasion) into the areas that contain these resources. This occupation continues with its slow, silent, although progressive march, threatening precious and irreplaceable resources. From this background an area in the direct vicinity north-east of Curitiba has been studied. In this area a drinking water reservoir was constructed in the time that the study took place in the Iraí-basin. The Iraí-reservoir even though an area around the lake will be protected may be polluted by two tributaries which flow through more or less densely populated areas. In the study area on the same time wells have been constructed. To estimate what the impact may be from the possibly polluted reservoir on the aquifer a groundwater flow model has been constructed. On the same time to estimate the water balance and the spatial distribution of pollution vulnerability the hydrological model MODBIL has been used. Also other methods have been used to estimate the pollution vulnerability to make a comparison and because none of the methods takes every aspect into account. With the calibrated groundwater flow model for the situation before the construction of the Iraí-reservoir and after its construction, simple particle tracking transport models are constructed as scenarios how the water of the aquifer may be influenced.