Cristian-Ioan POP¹, Artur IONESCU^1*, Călin BACIU^1
1Babeş-Bolyai University, Faculty of Environmental Science and Engineering, str. Fantanele 30,
Cluj-Napoca, Romania, *Corresponding author – artur.ionescu@ubbcluj.ro

METHANE SEEPAGE FROM GEOLOGIC SOURCES ON THE MOLDAVIAN PLATFORM (EASTERN ROMANIA)

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The paper describes the gas emitting features from the Moldavian Platform, including the first direct measurements of the methane flux from geologic sources in this region. The gas is released from relatively small mud volcanoes and seepage areas, most of them currently exhibiting a weak activity. The mud volcanoes are often covered by a crust of dry mud. The closed chamber method with in-situ measuring of the methane flux has been used for assessing the gas output from the seeps. The methane fluxes measured on 20 seeps distributed in the eastern part of the Moldavian Platform are in the range of 10² – 10⁶ mg m^-2 d^-1. The calculated output of the individual gas seeps varies in the range 10^-3 – 10¹ t y^-1 CH4. The observed activity of the gas seeps seems to be lower than several decades ago, as described in the literature. No commercial oil and/or gas reservoirs are known in the investigated area, although some exploration wells have been drilled, and low amounts of gas have been found. The obtained data allows a better understanding of the natural degassing process on the Moldavian Platform. The gas-emitting features are relatively densely distributed, especially along rivers, suggesting the importance of erosion in creating pathways for the degassing of sediments. This first set of data is of particular interest as a baseline for any future hydrocarbon exploration works, especially taking into account the inferred shale gas potential of the Moldavian Platform. The present work also contributes to the enlargement of the Romanian and global databases of methane flux to the atmosphere.