MINERAŁY ILASTE W PIASKOWCACH KARBONU Z POŁUDNIOWO-WSCHODNIEJ CZĘŚCI BASENU LUBELSKIEGO JAKO WSKAŹNIKI PALEOTEMPERATUR DIAGENEZY

Abstract

CLAY MINERALS IN THE CARBONIFEROUS SANDSTONES OF THE SOUTHEASTERN PART OF THE LUBLIN BASIN AS PALEOTEMPERATURE INDICATORS OF DIAGENESIS

Abstract. Clay minerals are the main components of the Carboniferous sandstones cement in the Lublin Basin. The allogenic minerals included in the matrix and authigenic minerals forming cements were distinguished among clay minerals. The following research methods were used in the paper: polarizing microscope, cathodoluminescence, scanning electron microscope, X-ray diffraction analyses, infrared studies and isotopic age K-Ar of diagenetic illite. The main authigenic clay minerals in the Carboniferous sandstones are kaolinite subgroup minerals – vermiform kaolinite and blocky kaolinite and dickite. In a smaller amounts are: fibrous illite, chlorites and illite/smectite mixed-layered mineral. Vermiform kaolinite and chlorite rims were crystallized in eodiagenesis. Blocky kaolinite and dickite, illite/smectite mixed-layered minerals and fibrous illite were formed above 50°C in mezodiagenesis. The transformation of kaolinite to dickite indicates the temperature at about 120°C. Determination of the K-Ar age of crystallization of the diagenetic illite – about 260 My ago suggests that the Carboniferous deposits have reached the maximum temperature of about 160°C in the Early Permian.