A FLUORESCENCE CONTRIBUTION TO THE RECOGNITION OF FLUIDS TRAPPED IN MINERALS IN THE CARPATHIAN OUTCROPS

Abstract

Based on the assumption that fluorescence studies are an important tool in search and characterization of hydrocarbons, samples of rocks, minerals and the organic matter were collected in the Western Carpathian area spreading from the Mszana Górna region in the west to the Bieszczady Mts. in the east, and continuously, towards SE outside the Polish frontier, in Ukraine and Slovakia. Analytical procedures comprised preparation, microscopic observation of the material (organic matter and minerals) from the point of view of inclusions and fluorescence followed by detailed luminescence studies. Those steps have been followed by the microthermometric determinations. The application of the fluid inclusion methods, which are one of the newest analytical tools in the last two decades have led to the characteristics of fluids trapped in the inclusions in the area. The fluorescence studies showed some diversity of hydrocarbons both in compositions and in distribution. The analyses were performed in double-sided polished thin sections prepared based on cold techniques. Fluorescence of inclusions in two minerals, quartz and calcite, was checked in those specific thin sections either in glued wafers, or loose (single) crystals. The fluid inclusion studies were accompanied later on by solid organic matter inclusion studies. Those point to the presence of the following minerals: quartz, dolomite, calcite, clay minerals, gypsum with anhydrite admixture, traces of pyrite and siderite, feldspars. General distribution of fluorescing and not fluorescing inclusions suggests the presence of light hydrocarbons (methane) in the west and south of the area, being enriched in higher hydrocarbons (oil) towards the east.