Zdjęcie szlichowe okolic Sierpnicy (Góry Sowie)

Andrzej Grodzicki, Tomasz Kułakowski




The results of schlich studies being carried out in the area of the Sierpnica vicinity in the Góry Sowie (Mts.) have been presented in this article. The studies cover the observations made on the series of rocks at 40 exposures when probing 120 schlich samples analyzed in the Laboratory of Mineralogy and Petrography Department of the Wrocław University. The authors have ascertained the possibility of separating several groups of heavy minerals occurring in outwash deposits when applying directly the schlich method. These groups of heavy minerals vary according to the character of different subtypes of rocks oocurring in the Góry Sowie (Mountains). The most characteristic minerals making up the oligoclase-biotite gneisses and adjacent rocks are: biotite, hornblende, garnets, cyanite and apatite. The microclinic two-mica gneisses contain such minerals as: turmaline, topaz, pyroxens and sillmanite. Both gneisses are dominated in schlich by ilmenite and haematite. Mineral assemblage: turmaline - topaz existing in alluvial deposits when forming gneisses may indicate the fact that the rock-complex mentioned above can undergo greisening process. Alluvial deposits superimposing the Culm series ore bearing less rounded heavy minerals, a large amount of ore-forming minerals and biotite. Within the remote distance from the gneiss concentration zone one can ascertain the increasing number of ore-forming minerals, the decreasing number of other minerals content featuring a constant increase in the degree of roundness. Single grains of olivines appeared in the surrounding area of the melaphyre occurrence zone. The degree of roundness pertained to heavy minerals depends largely upon the resistivity of these minerals against the chemical and mechanical processing factors as well as the transport distance. The heavy minerals of the Upper Carboniferous and Rotliegendes deposits feature significantly better degree of roundness.

Full Text: