Badania petrograficzno-geochemiczne utworów dolnego cechsztynu wiercenia w Lęborku

Abstract

PETROGRAPHICAL AND GEOCHEMICAL INVESTIGATIONS OF LOWER ZECHSTEIN SEDIMENTS FROM LĘBORK BORE-HOLE

This paper contains the results of the petrographical and geochemical investigations made by the authors of the Lower Zechstein from the Lębork bore-hole in Pomerania. This research was based on samples taken from the conglomerates, the sandstones, the bituminous shale and the dolomites; altogether, these rocks comprise a height of some dozens of meters from depth 978.75 m. to 1027.70 m.

The-authors present their micrometric analyses of the mineral composition of the rocks mentioned, and of the-heavy fraction found in the samples collected from the sandstones and conglomerates. They also show the results·of their quantitative spectral and colourimetric determinations of several characteristic trace elements, such as: Cu, Zn, Ph, Ni, Co, Mo and V. Moreover, they investigated the distribution of these trace elements in the lithological column examined, as well as the interdependence between the content of these trace elements and the bitumina content of the rocks.

The Lower Zechstein sediments of the Lębork bore-hole are sparingly mineralized by. copper, lead and zinc. Of ore minerals containing these metals the authors determined: chalcopyrite, galena, sphalerite, alongside other minerals like pyrite, marcasite and magnetite.

The elements: Cu, Zn, Co, Ni, Mo and V are distinctly concentrated in parts of the bituminous shale. Pb appears concentrated in the bottom strata of the dolomites. In the remaining rock layers, the quantity of these elements does not exceed the average occurring in similar rock types, with the exception of zinc which appears in larger quantities. In the samples examined, the authors determined an interrelation in occurrence between vanadium, molybdenum, nickel and bitumina, between nickel and cobalt, between molybdenum and vanadium, and between nickel and vanadium.