The nature of the isotopically heavy carbon of carbon dioxide and bicarbonates in the waters of mud volcanoes in Azerbaijan

Application of brine differentiation and Langelier–Ludwig plots to fresh-to-brine waters from sedimentary basins: Diagnostic potentials and limits

“…1C). Most probably, in the mud volcano waters the Na-bearing silicate hydrolysis is enhanced by hydrocarbon oxidation-biodegradation, a process characterized by heavy δ 13 C(CO 2 ) up to +20‰ and occurring at shallow depth (b2000 m) and low temperature (b70°C) (Capozzi and Picotti, 2002;Feyzullayev and Movsumova, 2010;Pallasser, 2000). Reading key (inset redrawn from Hounslow, 1995); G and H are gypsum and halite precipitation points after seawater evaporation (Pierre, 1982).…”

Structure of mud volcano systems and pockmarks in the region of the Ceuta Contourite Depositional System (Western Alborán Sea)

“…These structural elements reflect major episodes of mudreactivation directly not only from the deep source, but also from mud-remobilization of former buried mud volcanoes. Remobilization and compaction of the buried mud volcanoes can produce dewatering and upward flows of product sourcing from diagenetic processes as CO 2 from anaerobic oxidation of methane (Feyzullayev and Movsumova, 2010). These mechanisms could promote fluid overpressure and the subsequent new eruptive events of a mix of hydrocarbon fluids, sediments and diagenetic products from buried ancient mud volcano edifices.…”

Active sulfur cycling by diverse mesophilic and thermophilic microorganisms in terrestrial mud volcanoes of Azerbaijan

“…Azerbaijan and its offshore expanses in the Caspian Sea represent one of the most densely populated regions of mud volcanoes and mud volcanism is one of the major factors controlling oil and gas fields in the region. Unusually high δ 13 C values of CO 2 and bicarbonates in the TMVs are thought to result from biodegradation of oil (Feyzullayev and Movsumova, ); however, very little is known about the microbial communities in these volcanoes. Multiple studies have characterized the complex plumbing system of the TMVs that are capable of transporting mud and fluids from origins as deep as 10 km or greater (Planke et al ., and references therein; Mazzini et al ., ), and records of eruption history as well as geochemical and isotopic compositions of emitted oil, gas, mud and water exist for several prominent TMVs in the region (Guliyev et al ., ; Planke et al ., ; Etiope et al ., ; Mazzini et al ., ; Feyzullayev and Movsumova, ).…”

“…Terrestrial mud volcanoes (TMVs) occur where high fluid pressure in the deep subsurface results in the transport of mud, water and gas to the surface (Feyzullayev and Movsumova, 2010;Niemann and Boetius, 2010). This process creates diverse morphological features rich in methane and other hydrocarbons (Dimitrov, 2002), and hosting a suite of electron acceptors including oxygen, nitrate, iron, manganese and sulfate (Planke et al, 2003;Alain et al, 2006;Mazzini et al, 2009;Chang et al, 2012).…”