In the sedimentary environments of the Pannonian Basin (PB) in central Europe, CO2 filled layers are located in many sites. In addition to that research of CO2 fields has an emphasized importance, such as a natural analogue of the capture and sequestration the industrial CO2, the gas fields contain primordial and ancient trace gases. Analyzing these components we can better understand the processes during the formation of the Earth. Our recent study has shown that the CO2 from the gas fields near Répcelak is originated from the degassing of the upper-mantle and Pliocene intrusions. This CO2 is ascending and being mixed with nitrogen and hydrocarbon gases produced from the sedimentary organic matter, and then it is stacked beneath the impermeable layers. Based on the helium isotope ratios of the gases it has been found that the 25-60% of He is of mantle-derived and the remaining He component is added during the residence time in the reservoir rock and the up-flow of CO2 . The amount of radiogenic argon is the gases, as the high 40Ar/36Ar showed, refers to the age of gas fields. The argon is expected to be very old. One goal of our research is to investigate how this argon could be used in promising dark matter research. This presentation was used for the Low-Radioactivity Underground Argon Workshop held at Pacific Northwest National Laboratory in Richland, Washington on March 19 - 20, 2018.