X-ray determination of brushite (CaHPO4 · 2H2O) suspended in the water of the Neckar River,west Germany

The results reported in the present paper are a by-product of a detailed study of the heavy metals (Zn, Pb, Cu, Cd, Co, Ni, Cr, Fe, Mn) carried by the Upper Neckar River, Germany. The purpose was to determine the pollution by industrial waste of the river waters (Abadian 1976). In order to elucidate the various mechanisms of heavy-metal transport in the river, the clay of the bottom sediments and that carried in suspension was analysed for the metals at a number of locations and subjected to X-ray diffraction for the determination of the clay minerals present. The bottom sediments consist of kaolinite, illite, random interstratification (of mica and expandable layers) and quartz. In some samples chlorite and calcite were detected as well. The mineral content of the suspended load was collected by pressure filtration on porous ceramic plates. The clay minerals determined by subjecting the plates plus filtered residue to X-ray diffraction were the same as in the sediments. In addition to the clay-mineral reflections, three of the samples obtained from suspension (locations 2, 3, and 5 in the map, Fig. 1) showed the strongest diffraction line of the mineral brushite, CaHPO₄·2H₂O, at 7.6 Å. In one sample (location 2) three more lines of brushite were observed. The occurrence of brushite in the Neckar may be taken as a mineralogical indicator of the pollution of the river, because the following materials may be possible sources of the phosphate: artificial fertilizers, liquid manure, water softeners, detergents, and industrial waste waters.     

Petrographie,Stoßwellenmetamorphose und Entstehung polymikter kristalliner Breccien im Nördlinger Ries

Polymict cristalline breccias are typical impact products of the Ries crater. They occur within the Ries crater (Appetshofen, Lierheim, Leopold Meyers Keller), on its rim (Maihingen-Klostermühle) and within the immediate vicinity of the crater (Itzing). Apart from very rare admixtures of sedimentary rock fragments the polymict cristalline breccias consist almost exclusively of fragments of various cristalline rocks, namely granites, gneisses and amphibolites. The petrographical and statistical investigations have shown that breccias from different localities have different composition. This reflects a possible difference in local compositions of the cristalline basement. The rocks in the breccias have been affected to various degress by shock metamorphism. The amphibolites could thus be shown to belong predominantly to stage I (diaplectic quartz and feldspar, 100–300 kb) and stage II (diaplectic quartz and feldspar glasses, 350–500 kb) whereas the granites and geisses can be attributed mostly to stage 0 (fractured quartz and feldspar, <100 kb) and stage I. This is in part the result of the bulk shock wave impedance of the rocks in question.Deformation structures resulting from shock metamorphism have been observed for the first time in sphene as well as in various planes of apatite.A large part of breccia rocks, which contain diaplectic quartz and feldspar glasses were altered into montmorillonite at a later date. The authigenic minerals were examined by x-rays and chemically by microprobe analysis.

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Herrn Prof. Dr. W. von Engelhardt danke ich für Diskussion und Beratung. Dem Bundesministerium für Bildung und Wissenschaft sei für die finanzielle Unterstützung dieser Arbeit gedankt.