Mineralizacja kruszcowa w utworach kambru i prekambru południowej części niecki podlaskiej

Abstract

MINERALIZATION OF THE CAMBRIAN AND PRECAMBRIAN ROCKS IN THE SOUTH PART OF THE PODLASIE SYNCLINE (NE POLAND) Summary The paper discusses ore mineralization of the Cambrian and Precambrian rocks of the south part of the Podlasie syncline (N PoIand) on the basis of the material obtained in boreholes Polaki, Zembry, Biała Podlaska 2 and Terespol 1. Ore mineralization was noted only in boreholes Biała Podlaska 2 and Polaki. The marcasite mineralization was found in borehole Biała Podlaska 2, in a c. 40 m. sequence of sandstones of the Middle Cambrian, in which an abundant (20-30%) marcasite matrix, most probably diagenetic was present (PI. 1 Figs. 1-2). In borehole Polaki ore mineralization was found at three basic levels of Cambrian sandstones. The first level (the Protolenus horizon) is metallized with argentite, native silver, pyrite, ilmenite, limonite and getite. The concentration of argentite in the form of veins (PI. 1, Figs. 3-4; PI. 2, Fig. 1) connected with migration of silver sulphate and its precipitation in the medium of acidic reaction in the presence of ferrite bitter. The second level (the Holmia horizon) contains pyrite, marcasite (Pl. 2, Figs. 2-3) and - from non-metallic mineralization - siderite and bitumines. This metallization owes its final form to the processes of metamorphic differentiation which created the front of mineralization strongly transforming the rock. The third level (the sub-Holmia horizon) is characterized by the occurrence of pyrite concretions (PI. 2, Fig. 4), most probably of hypergenic origin.