Główne i poboczne składniki chemiczne w amerykańskich, francuskich i niemieckich wzorcowych próbach skał

Henryk Pendias




In studies chemical composition of geological materials particular attention is paid to the adaption  of adequate methods that would take into account all modern and effective physical and chemical apparatuses. However, apart from any method applied, natural standard characterized by the mineral composition approximate to the samples examined should be a reference point and a factor that would allow us to control the results obtained. These pattern's should be precisely determined as concerns their chemical composition. This, however, can be made only be means of analyses performed in various laboratories using various methods.
The following are 9 rock patterns estimated to be of international importance at present: two American standards – granite G-l and diabase W-1; three French standards – granites GA and GH, and basalt BR; four German standards – granite GM, basalt BM, shale TB and limestone KH.
The American patterns are characterized by a complete documentation of macro- and micro-composition, based on the analyses made in some scores of laboratories in many countries.
The mam, and secondary chemical components of the French standards were determined in 115 various analytical centers.  On account of a small amount of analyses of trace elements, and due to considerable differences observed between the individual determinations, the results obtained require additional elaborations.
Analyses of the chemical components in the German standards ZGI have been made in the Laboratories of the Geological Surveys of Bulgaria, Czechoslovakia, German Democratic Republic, Poland, Hungary and USSR. Analytical works having in view a univocal determination of composition of trace elements are carried on at present.
To compare the characteristic of the chemical composition of the 9 standards discussed, the results of analyses and statistical data were collected from source materials and put together in tables (Tables 1–15). Figs. 1–8 illustrate the dependence of the value of relative deviation (C) upon the average content of a given component. It results from the diagrams that the highest relative deviations are mainly concerned with the small contents of the component. In the case of a very low content of the given component, amounting to 0,1% the value of the relative deviation increases up to some scores per cent. Moreover the determinations of certain main and secondary chemical components such as Fe2O3, Fe2O, MgO, CaO, Na2O and H2O+ are characterized by a relatively high value of C. In the light of off the chemical components the evaluation of the determinations of SiO2 and Al2O3 seems to be positive.
In Tables 16 and 17, the intervals of the contents of the individual components defined by the values x–y and x+s (according to Grassmann, 1966) are given for 4 German patterns ZGI. Furthermore, there are also given average contents (x1, x2, x3) from the determinations made in 3 laboratories of Polish Geological Survey. Mean contents (x1, x2 and x3) are for the most part, included in an interval from x – s to x + s.

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