Gas hydrates in the Ginsburg and Yuma mud volcano sediments (Moroccan Margin): results of chemical and isotopic studies of pore water

Ferromanganese nodules and micro-hardgrounds associated with the Cadiz Contourite Channel (NE Atlantic): Palaeoenvironmental records of fluid venting and bottom currents

“…This assumption is supported by the high oxygen isotopic values obtained in the carbonates from the nodules, up to +4%0, which could indicate dissociation of gas hydrates. It must also be considered that several authors have reported the presence of gas hydrates in deep-water mud volcanoes in the Gulf of Cadiz, and that the Iimit of the stability zone for hydrates is located in the study area (Gardner, 2001;Mazurenko et al, 2003;Pinheiro et al, 2003;). In the seismic profiles from the CCC we can observe the presence of buried mud diapir structures and fluid flow from the diapirs to the CCC (Fig.…”

A predictive numerical model for potential mapping of the gas hydrate stability zone in the Gulf of Cadiz

“…1). Hydrates and hydrocarbon gases sampled from mud volcano sediments include both biogenic and thermogenic components (Blinova and Stadnitskaia, 2001 ;Mazurenko et al, 2003;Stadniskaia et al, 2006). 3.…”

“…The gas hydrocarbon composition (CI-C s ) was measured during the scientific TTR-9 cruise in cores AT-201G, AT-203G and AT-208G by chromatographic analysis (Stadnitskaia et al, 2000). AT-203G (Yuma mud volcano) and AT-208G (Ginsburg mud volcano) contained allochthonous thermogenic gas, whereas AT-201G (pelagic sediments) contained autochthonous gas of microbiologic origin (biogenic) (Stadnitskaia et al, 2000(Stadnitskaia et al, , 2001(Stadnitskaia et al, , 2006Blinova and Stadnitskaia, 2001;Mazurenko et al, 2003).…”

Origin and transport of pore fluids in the Nankai accretionary prism inferred from chemical and isotopic compositions of pore water at cold seep sites off Kumano

“…Cl − concentrations in the pore fluids at the bacterial mats are lower than that in seawater (SW) (Toki et al 2004). Deviations of the chemical and isotopic compositions of the pore fluids from those of SW have been attributed to the mixing of fluids with compositions differing from those of SW (Kastner et al 1991;Tsunogai et al 2002;Dählmann and de Lange 2003;Mazurenko et al 2003;Toki et al 2004;Hiruta et al 2009). Since each of these fluid sources is characterized by specific O and H isotopic compositions (e.g., Kastner et al 1991).…”