First discovery and formation process of authigenic siderite from gas hydrate–bearing mud volcanoes in fresh water: Lake Baikal, eastern Siberia

We report on the first authigenic siderite (FeCO3) concretions recovered from near‐bottom sediments at gas hydrate‐bearing mud volcanoes in fresh water (Lake Baikal, Eastern Siberia). The carbonates appear as firm ‘plate‐type’ formations at the Malenky mud volcano (Southern Baikal Basin) and as soft nodules at the K‐2 mud volcano (Central Baikal Basin). Calcium is the main divalent component which substitutes iron in the carbonate lattice (7 to 20 mol%). The δ13C values of the carbonates (+3.3 to +6.8‰ at Malenky, and +16.5 to +21.9‰ PDB at K‐2) indicate that their formation is due to methanogenesis. The latter was most likely caused by the microbial methyl‐type (acetate) fermentation that is suggested from the isotopic composition of the accompanying methane hydrates and dissolved methane. General depletion of the siderites in 18O (−11.6 to −9.9 ‰ at Malenky, and −13.9 to −12.3‰ PDB at K‐2) is mainly inherited from the isotope composition of pore water (−15.2 to −15.4‰ SMOW) at ambient temperature (3.5°C).

[1]  Akihiro Hachikubo,et al.  Coexistence of structure I and II gas hydrates in Lake Baikal suggesting gas sources from microbial and thermogenic origin , 2006 .

[2]  A. Aldahan,et al.  Sedimentary facies and climate control on formation of vivianite and siderite microconcretions in sediments of Lake Baikal, Siberia , 2006 .

[3]  Alexander A. Prokopenko,et al.  Depleted methane-derived carbon in waters of Lake Baikal, Siberia , 2005, Hydrobiologia.

[4]  A. Lein,et al.  Authigenic Carbonate Formation in the Ocean , 2004 .

[5]  V. Soloviev,et al.  Gas hydrate accumulation in the subsurface sediments of Lake Baikal (Eastern Siberia) , 2003 .

[6]  L. P. Golobokova,et al.  Methane hydrates in deep bottom sediments of Lake Baikal , 2003 .

[7]  M. Vanneste,et al.  Sublacustrine mud volcanoes and methane seeps caused by dissociation of gas hydrates in Lake Baikal , 2002 .

[8]  Jizhong Zhou,et al.  Temperature-dependent oxygen and carbon isotope fractionations of biogenic siderite , 2001 .

[9]  J. Greinert,et al.  Gas Hydrate‐Associated Carbonates and Methane‐Venting at Hydrate Ridge: Classification, Distribution, and Origin of Authigenic Lithologies , 2001 .

[10]  Michael J. Whiticar,et al.  Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane , 1999 .

[11]  D. L. Parkhurst,et al.  User's guide to PHREEQC (Version 2)-a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations , 1999 .

[12]  A. Duchkov,et al.  THE FIRST FIND OF GAS-HYDRATES IN THE SEDIMENTARY ROCKS OF LAKE BAIKAL , 1998 .

[13]  T. Barth,et al.  Deep marine biosphere fuelled by increasing organic matter availability during burial and heating , 1997, Nature.

[14]  A. Kopf,et al.  7. ISOTOPE GEOCHEMISTRY OF SYNTECTONIC CARBONATE CEMENTS AND VEINS FROM THE OREGON MARGIN: IMPLICATIONS FOR THE HYDROGEOLOGIC EVOLUTION OF THE ACCRETIONARY WEDGE1 , 1995 .

[15]  William Davison,et al.  Iron and manganese in lakes , 1993 .

[16]  R. Weiss,et al.  The major and minor element geochemistry of Lake Baikal , 1991 .

[17]  Carolyn A. Koh,et al.  Clathrate hydrates of natural gases , 1990 .

[18]  E. Suess,et al.  7. CARBONATE CEMENTATION OF GRANULAR AND FRACTURE POROSITY: IMPLICATIONS FOR THE CENOZOIC HYDROLOGIC DEVELOPMENT OF THE PERU CONTINENTAL MARGIN1 , 1990 .

[19]  R. Matsumoto.  Isotopically heavy oxygen-containing siderite derived from the decomposition of methane hydrate , 1989 .

[20]  R. Rosenbauer,et al.  Experimental oxygen isotope fractionation between siderite-water and phosphoric acid liberated CO2-siderite , 1988 .

[21]  S. Sheppard,et al.  An isotopic study of siderites, dolomites and ankerites at high temperatures☆ , 1986 .

[22]  S. I. Golyshev.  Fractionation of stable oxygen and carbon isotopes in carbonate systems , 1981 .

[23]  M. Coleman,et al.  Isotopic evidence for source of diagenetic carbonates formed during burial of organic-rich sediments , 1977, Nature.

[24]  R. H. Becker,et al.  Oxygen isotope study of a Precambrian banded iron-formation, Hamersley Range, Western Australia , 1976 .

[25]  W. D. Rosenfeld,et al.  Carbon Isotope Fractionation in Bacterial Production of Methane , 1959, Science.