The pseudovolcanic microrelief on the whole is totally dependent on local accumulations of natural gas from Sarmatian layers and groundwater or infiltration. Small gas deposits get into contact with water, soften and dissolve the layers of fine marl clay rocks. Between the Prut and the Siret,on the territory of Romania, there are several alignments of "mud stove/ muddy volcanoes" along the valleys that cross the hilly plains of Jijia-Bahlui and on its geomorphological contact. Between the Prut and the Nistru, in The Republic of Moldova there are five mud volcanoes areas located in the tectonic faults, active mostly during earthquakes and heavy rains.