Oxyreactive Thermal Analysis of Dispersed Organic Matter - a Good Tool for Investigation of Geothermal Systems

Abstract

Data from the Oxyreactive Thermal Analysis (OTA) - a new method, introduced in the last years to geology - were used to document the indicative features of dispersed organic matter (DOM). DOM in rocks is a useful tool for investigations of thermal evolution of host rocks. The example of DOM features applicability in the investigations of geothermal Podhale system is presented in this paper. OTA results allow to distinguish the DOM transformation stages as well as the heating-up of the investigated rock-complexes. These results could form also the base for the better reconstruction of the thermal history of any rock-complexes, including paleothermal and current thermal regime. That could be applied especially to low-enthalpy geothermal sedimentary systems, rich in organic matter and hydrocarbons. In such systems a combination of mineralogical methods and DOM investigation methods (including thermal transformation of illite-smectite group serving as a geothermometer) to recognize the evolution and current state of the low-enthalpy systems, usually gives good results. The low-enthalpy systems were often potentially generating energy sources - geothermal waters and hydrocarbons - and at present they also contain both geothermal waters and hydrocarbons (i.e. gaseous hydrocarbons dissolved in water).
The obtained results point out a distinct differences of OTA features of organic matter from Mesozoic basement of Podhale system (containing geothermal aquifers) when compare to organic matter dispersed in impermeable Paleogene Flysch cover. The results point out also some convergences to tectonic processes in rock-complexes.
In the presented paper we also suggest the applicability of new OTA method to the investigations of the geothermal systems.