Bazalty z rejonu Huminy (Rybnicki Okręg Węglowy)

Abstract

Opisano bazalty nawiercone w otworze wiertniczym S-7 w rejonie Suminy. Są to skały o strukturze porfirowej, teksturze bezładnej. Wśród prakryształów oznaczono augit i pseudomorfozy po oliwnie, w cieście skalnym – pirokseny, magnetyt i nefelin.Z minerałów wtórnych wydzielono zeolity i węglany. Bazalty te są podobne do bazaltów występujących na Śląsku Opolskim i stąd wysnuto wniosek, że należą one do trzeciorzędowej formacji bazaltowej. BASALT FROM THE SUMINA AREA (RYBNIK COAL BASIN)The borehole S-7 penetrated 3 basalt veins 85 to 90 cm thick in the Gruszowskie beds in the Sumina area. The rocks forming the veins display porphyric structure and random texture. Phenocrysts are represented by augite and post-olivine pseudomorphs infilled with carbonates and minerals of the serpentine group, and the matrix – by fine-grained pyroxenes, magnetite and nepheline. The secondary minerals identified include zeolites and carbonates. This basalt resembles those from the Opole Silesia in mineral and chemical composition so it was inferred that it also belongs to the Tertiary basalt formation.The intrusion penetrated Carboniferous sandstones and claystones. Regeneration of quartz grains and formation of secondary albite and biotite took place at the contact with sandstones. Among clay minerals, illite and montmorillonite predominate but not kaolinite. Organic matter was alterated into natural coke and the pores in coke became clogged with carbonates. The alterations took place in result of both temperature effect of intruding magma and the hydrothermal solutions. A high content of methane found in the borehole S-7 may be explained by heating of the rock massif by intruding magma.