Nikiel w glebach nad skałami ultrazasadowymi i zasadowymi w rejonie Woliborza, Sobótki i Przedborowej

Abstract

NICKEL IN SOILS OVERLYING ULTRABASIC AND BASIC ROCKS IN THE REGION OF WOLIBÓRZ, SOBÓTKA AND PRZEDBOROWASummaryDuring the prospections made for sulphide nickel ores a soil survey has also been performed at several outcrops of basic and ultrabasic rocks found to occur within the gneissic massif of the Sowie Mountains.Above the outcrops of the rocks here considered some soil samples have been taken, about 20 m apart, along several profiles. After drying, the sample have been sieved though a brass sieve, 3.0 and 0.12 mm in mesh diameter, and then silt fraction has been analysed to determine Ni, Co, Cu, Cr and V contents.The results obtained (contents in ppm) are as follows: Przygórze – serpentinites and dolomites: < 200 – 6000 Ni, < 40 - 6000 Cu; Szklary – serpentinites: to 1900 Ni, to 17 Co, to 240 Cu, 90 V (on average), to 40 000 Cr; Wolibórz – gabbros: < 200 - 2200 Ni, to 114 Co, < 41 – 1200 Cu; Sobótka – gabbros: to 180 Ni, to 60 Co, to 300 Cu, to 300 V, to 800 Cr; Przedborowa – amphibolites: to 300 Ni, 10 – 200 Co, 10 – 60 Cu, 20 - 1000 V, and more than 300 Cr.The examinations have demonstrated that .the chemical elements analysed occur in changing amounts. The highest nickel and chromium concentrations are observed in soils that overlie the ultrabasic rocks. Most propably, the rock-forming magnesium-iron silicates are here sources of nickel, cobalt and vanadium ions, chromites – of chromium ions, and sulphide mineralization of basement rocks – of copper ions.