Authigenic carbonates from the Darwin Mud Volcano, Gulf of Cadiz: A record of palaeo-seepage of hydrocarbon bearing fluids

Vanneste, Heleen; Kastner, Miriam; James, Rachael H.; Connelly, Douglas P.; Fisher, Rebecca E.; Kelly-Gerreyn, B.A.; Heeschen, Katja; Haeckel, Matthias; Mills, Rachel A.

doi:10.1016/j.chemgeo.2012.01.006

Cited by 27 publications

(9 citation statements)

References 105 publications

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“…Aragonite, Mg-calcite, and dolomite are typical authigenic carbonates encountered at cold seep environments [Baker et al, 1981;Bayon et al, 2007Bayon et al, , 2009Burton, 1993;Burton and Walter, 1987;Cangemi et al, 2010;Cremiere et al, 2012;Feng and Roberts, 2011;Feng et al, 2009;Himmler et al, 2010;Moore et al, 2004;Pierre et al, 2012;Vanneste et al, 2012]. They all imply an uptake of bicarbonate, calcium, magnesium, and strontium from the surrounding pore water during their formation; and reciprocally they all release those elements when undergoing a dissolution process.…”

Section: Carbonate-associated Processesmentioning

confidence: 99%

Pore water geochemistry at two seismogenic areas in the Sea of Marmara

Ruffine

Germain

Polonia

et al. 2015

Geochem Geophys Geosyst

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Within the Sea of Marmara, the highly active North Anatolian Fault (NAF) is responsible for major earthquakes (Mw 7), and acts as a pathway for fluid migration from deep sources to the seafloor. This work reports on pore water geochemistry from three sediment cores collected in the Gulfs of Izmit and Gemlik, along the Northern and the Middle strands of the NAF, respectively. The resulting data set shows that anaerobic oxidation of methane (AOM) is the major process responsible for sulfate depletion in the shallow sediment. In the Gulf of Gemlik, depth concentration profiles of both sulfate and alkalinity exhibit a kink-type profile. The Sulfate Methane Transition Zone (SMTZ) is located at moderate depth in the area. In the Gulf of Izmit, the low concentrations observed near the seawater-sediment interface for sulfate, calcium, strontium, and magnesium result from rapid geochemical processes, AOM, and carbonate precipitation, occurring in the uppermost part of the sedimentary column and sustained by free methane accumulation. Barite dissolution and carbonate recrystallization have also been identified at deeper depth at the easternmost basin of the Gulf of Izmit. This is supported by the profile of the strontium isotope ratios ( 87 Sr/ 86 Sr) as a function of depth which exhibits negative anomalies compared to the modern seawater value. The strontium isotopic signature also shows that these carbonates had precipitated during the reconnection of the Sea of Marmara with the Mediterranean Sea. Finally, a first attempt to interpret the sulfate profiles observed in the light of the seismic activity at both sites is presented. We propose the hypothesis that seismic activity in the areas is responsible for the transient sulfate profile, and that the very shallow SMTZ depths observed in the Gulf of Izmit is likely due to episodic release of significant amount of methane.

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Section: Carbonate-associated Processesmentioning

confidence: 99%

Pore water geochemistry at two seismogenic areas in the Sea of Marmara

Ruffine

Germain

Polonia

et al. 2015

Geochem Geophys Geosyst

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“…The widespread occurrence of massive authigenic carbonate chimneys and crusts typically at depths between 600 and 1200 m along the margins of Morocco and Spain suggests that this was a very active seepage area in the past (Wehrmann et al, 2011;Magalhães et al, 2012;Vanneste et al, 2012). In these carbonate provinces there are frequent observations of mounds, thickets and debris of mostly dead cold-water scleractinian corals (Wienberg et al, 2009) and also extensive buccinid and mytilid graveyards (usually within the crater of the mud volcanoes).…”

mentioning

confidence: 99%

Macrofaunal assemblages from mud volcanoes in the Gulf of Cadiz: abundance, biodiversity and diversity partitioning across spatial scales

Cunha¹,

Rodrigues²,

Génio³

et al. 2012

Preprint

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The Gulf of Cadiz is an extensive seepage area in the South Iberian Margin (NE Atlantic) encompassing over 40 mud volcanoes (MVs) at depths ranging from 200 to 4000 m. The area has a long geologic history and a central biogeographic location with a complex circulation assuring oceanographic connectivity with the Mediterranean Sea, Equatorial and Northern Atlantic regions. The geodynamics of the region promotes a notorious diversity in the seep regime despite the relatively low fluxes of hydrocarbon-rich gases. We analyse quantitative samples taken during the cruises TTR14, TTR15 and MSM01-03 in seven mud volcanoes grouped into Shallow MVs (Mercator: 350 m, Kidd: 500 m, Meknès: 700 m) and Deep MVs (Captain Arutyunov: 1300 m, Carlos Ribeiro: 2200 m, Bonjardim: 3000 m, Porto: 3900 m) and two additional reference sites (ca. 550 m). Macrofauna (retained by a 500 μm sieve) was identified to species level whenever possible. The samples yielded modest abundances (70–1567 ind. per 0.25 m2) but a number of species among the highest ever reported for cold seeps. Among the 366 recorded species, 22 were symbiont-hosting bivalves (Thyasiridae, Vesicomyidae, Solemyidae) and tubeworms (Siboglinidae). The multivariate analyses indicated significant differences between Shallow and Deep MVs: The environmental conditions at the Shallow MVs makes them highly permeable to the penetration of background fauna leading to high diversity of the attendant assemblages (H': 2.92–3.94; ES(100): 28.3–45.0; J': 0.685–0.881). The Deep MVs showed, in general, contrasting features but were more heterogeneous (H': 1.41–3.06; ES(100): 10.5–30.5; J': 0.340–0.852) and often dominated by one or more siboglinid species. The rarefaction curves confirmed the differences in biodiversity of Deep and Shallow MVs as well as the approximation of the latter to the reference sites. The Bray–Curtis dissimilarity demonstrated the high β-diversity of the assemblages, especially in pairwise comparisons involving samples from the deeper MVs. Diversity partitioning assessed for species richness, Hurlbert's expected number of species and Shannon–Wiener index confirmed the high β-diversity across different spatial scales (within MVs, between MVs, between Deep and Shallow MVs). We suggest that historical and contemporary factors with differential synergies at different depths contribute to the high α-, β- and γ-diversity of the mud volcano faunal assemblages in the Gulf of Cadiz

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“…Cold-seep carbonates consist of multiple Ca-Mg-carbonate phases. Aragonite, LMC, HMC, protodolomite, dolomite, and ankerite have been reported in cold seep or gas hydrate sites, such as the Gulf of Cadiz Merinero Palomares et al, 2012;Stadnitskaia et al, 2008;Vanneste et al, 2012), Gulf of Mexico (Birgel et al, 2011;Canet et al, 2006;Chen et al, 2007;Feng et al, 2014a;Ferrell and Aharon, 1994;Mansour and Sassen, 2011;Naehr et al, 2009;Roberts et al, 2010), Cascadia margin (Greinert et al, 2001;Kulm and Suess, 1990;Ritger et al, 1987;Teichert et al, 2005aTeichert et al, , 2005b, Norwegian Sea (Hovland et al, 2005;Mazzini et al, 2006), St. Lawrence Estuary (Lavoie et al, 2010), Japan Sea (Nehza et al, 2012), Black Sea (Bahr et al, 2010;Peckmann et al, 2001), Gulf of Guinea (Haas et al, 2010), Mediterranean Sea (Aloisi et al, 2000;Cangemi et al, 2010), Monterey Bay (Stakes et al, 1999), Ryukyu Island (Takeuchi et al, 2007), and South China Sea (SCS) (Chen et al, 2005(Chen et al, , 2006Ge et al, 2010;Han et al, 2008Han et al, , 2013Lu et al, 2010;Tong et al, 2013;Wang et al, 2014Wang et al, , 2012. In the cold seep area of Hydrate Ridge, two zones of carbonate phases have been identified: (1) the aragonite-and HMC-rich zone, located near the seafloor, and (2) the HMC-and (proto) dolomite-rich zone, which i...…”

Section: þHs àmentioning

confidence: 98%

“…However, these conditions are not available in a cold seep environment. Indeed, low or (Bahr et al, 2010;Birgel et al, 2011;Curtis and Coleman, 1986;Feng et al, 2014b;Greinert et al, 2001;Lu et al, 2010;Mazzini et al, 2004;Stadnitskaia et al, 2008;Takeuchi et al, 2007;Vanneste et al, 2012) and sulfide catalysis (Zhang et al, 2012a(Zhang et al, , 2013 are considered to be significant factors for the dehydration of Mg 2 þ and assisting Mg 2 þ in entering Cacarbonate lattice, forming HMC and (proto)dolomite. Both of these conditions are available near cold seep sites by AOM.…”

Section: Implication Of Cold Seep Activitiesmentioning

confidence: 99%