Isotopic-geochemical features of spontaneous gases from mud volcanoes in Eastern Georgia

Isotopic-geochemical study revealed presence of mantle He (3He/4He up to 223x10**-8) in gases from mud volcanoes of Eastern Georgia. This fact confirms that the Middle Kura basin fill encloses an intrusive body previously distinguished from geophysical data. Wide variations of carbon isotopic composition d13C in CH4 and CO2 and chemical composition of gas and water at temporally constant 3He/4He ratio indicate their relation with crustal processes. Unusual direct correlations of 3He/4He ratio with concentrations of He and CH4 and 40Ar/36Ar ratio can be explained by generation of gas in the Cenozoic sequence of the Middle Kura basin.

Determination of hydrocarbon gases in mud volcanoes in the Sorokin Trough

Hydrocarbon gases were determined in sediments from three mud volcanoes in the Sorokin Trough. In comparison to a reference station outside the mud volcano area, the deposits are characterized by an enrichment of high-molecular hydrocarbons (C2-C4), an absence of unsaturated homologues, a predominance of iso-butane in comparison with n-butane, and the presence of gas hydrate. The molecular composition of the hydrocarbon gases suggests their deep sources and thermogenic origin. In the pelagic sediments at the reference station, the methane concentration is relatively low (up to 49 ml/l); maximum concentrations are reached in deposits of the Dvurechenskii mud volcano (up to 400 ml/l). It was the first time that gas hydrate was sampled at the Dvurechenskii mud volcano. The gas extracted by dissociation of hydrate samples was dominated by methane (99.5%) with low amounts of ethane and propane (less than 0.5%). The isotopic composition of the methane varies between -62 and -66 per mill PDB in d13C, and between -185 and -209 per mill SMOW in dD, indicating a mainly biogenic origin with an admixture of thermogenic gas.

De Catalonia liber primus / Francisco Calça Barcinonensi ... auctore.

Marca tip. en P8v (Vindel, 315)

De Catalonia liber primus / Francisco Calça Barcinonensi ... auctore.

Marca tip. en P8v (Vindel, 315)

My experiments with volcanoes

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