Analiza inkluzji fluidalnych w wypełnieniach przestrzeni porowej skał czerwonego spągowca w wybranych rejonach Niżu Polskiego
Abstract
Fluid inclusion analysis of pore space fillings in Rotliegend rocks from selected regions of the Polish Lowlands.
A b s t r a c t. Fluid inclusions — tiny portions of palaeofluids trapped in minerals filling pore space in sedimentary rocks — were analysed. The studies covered carbonate, quartz and anhydrite cements in the Rotliegend rocks from several boreholes in north, north-western, central and south-west parts of the Polish Lowlands. They aimed at obtaining characteristics of fluid inclusions in the specific geological material, microthermometric measurements and use of fluid inclusions as geothermometer with reference to main petrological research conducted by A. Maliszewska and M. Kuberska in the above mentioned regions. Fluid inclusion studies comprised microscopic characteristics of these forms, fluorescence and cathodoluminescence observations and microthermometry. Due to different types of cements, different features of these inclusions have been observed. In general, the inclusions are two- or one-phase ones, primary and/or secondary, small, rare and hard to distinguish. Homogenisation temperatures of inclusions obtained in the studied samples lie in different intervals due to inclusion type and position. Generally they are above 100°C. Densities of fluids are differentiated and the systems are found to represent generally NaCl brines of changeable chemical systems. The microthermometric results have been compared with effects of analyses of light isotopes (carbon, oxygen) from the same cements. Data show presence of low- and high-temperature generations of cements.
A b s t r a c t. Fluid inclusions — tiny portions of palaeofluids trapped in minerals filling pore space in sedimentary rocks — were analysed. The studies covered carbonate, quartz and anhydrite cements in the Rotliegend rocks from several boreholes in north, north-western, central and south-west parts of the Polish Lowlands. They aimed at obtaining characteristics of fluid inclusions in the specific geological material, microthermometric measurements and use of fluid inclusions as geothermometer with reference to main petrological research conducted by A. Maliszewska and M. Kuberska in the above mentioned regions. Fluid inclusion studies comprised microscopic characteristics of these forms, fluorescence and cathodoluminescence observations and microthermometry. Due to different types of cements, different features of these inclusions have been observed. In general, the inclusions are two- or one-phase ones, primary and/or secondary, small, rare and hard to distinguish. Homogenisation temperatures of inclusions obtained in the studied samples lie in different intervals due to inclusion type and position. Generally they are above 100°C. Densities of fluids are differentiated and the systems are found to represent generally NaCl brines of changeable chemical systems. The microthermometric results have been compared with effects of analyses of light isotopes (carbon, oxygen) from the same cements. Data show presence of low- and high-temperature generations of cements.