Glacial-interglacial changes in organic carbon, nitrogen and sulfur accumulation in Lake Baikal sediment over the past 250 kyr

The waters of modern Lake Baikal circulate well and maintain oxic conditions for the entire lake in spite of its great depth. Past oxic/anoxic conditions in the water column are not known. Because reconstruction of paleo-redox conditions involved with climate changes provides information on dynamics of lake water circulation and biological activity, high-resolution analyses of total organic carbon (TOC), total nitrogen (TN) and total sulfur (TS) concentrations, and gamma ray density (GRD) were carried out using 492 sediment samples over the past 250 kyr (every other 1 cm from the 10 m core Ver98-1 St.5 taken from the Academician Ridge at 325 m water depth). Fifteen events of high TS/TOC ratio (>0.2 atomic) are observed; these are much larger than TS/TOC ratio of typical freshwater sediment (0.001–0.070) and also normal oxic marine sediments (0.13 in average). The sulfur occurs as pyrite by X-ray diffraction (XRD) analysis, probably being produced by sulfate-reducing bacteria (SRB). Such high TS/TOC ratios indicate high SRB activity in the lake and a high input of sulfate to the lake. A high TS/TOC layer often accompanies a decrease of TOC/TN ratio to ca. 5 (atomic). In particular, during a rapid cooling such as the Younger Dryas event, the TOC/TN ratio decreases steeply from 10.4 to 7.8 just prior to the increase of TS/TOC ratio from 0.02 to 0.55. Because the low TOC/TN ratio suggests low terrestrial organic matter contribution to the lake, saline water inflow from rivers could diminish to result in decreased water circulation in the lake. The rapid cooling event may restrict deep-water ventilation and create less oxic conditions in Lake Baikal.

[1]  M. Yoneda,et al.  Temporal changes in the phytoplankton community of the southern basin of Lake Baikal over the last 24,000 years recorded by photosynthetic pigments in a sediment core , 2002 .

[2]  K. Ikehara,et al.  Paleomagnetic record from Academician Ridge, Lake Baikal: a reversal excursion at the base of marine oxygen isotope stage 6 , 2002 .

[3]  K. Minoura,et al.  Erratum to “Palaeoenvironmental history of Lake Baikal during the last 23 000 years” [Palaeogeogr. Palaeoclimatol. Palaeoecol. 157 (2000) 95–108] , 2002 .

[4]  Frank R Rack,et al.  Derivation of δ18O from sediment core log data: Implications for millennial‐scale climate change in the Labrador Sea , 2001 .

[5]  C. Heip,et al.  Sulfur and iron speciation in surface sediments along the northwestern margin of the Black Sea , 2001 .

[6]  K. Kashiwaya,et al.  Orbit-related long-term climate cycles revealed in a 12-Myr continental record from Lake Baikal , 2001, Nature.

[7]  Michael Sarnthein,et al.  Potential links between surging ice sheets, circulation changes, and the Dansgaard-Oeschger cycles in the Irminger Sea, 60-18 kyr , 2000 .

[8]  K. Minoura,et al.  Palaeoenvironmental history of Lake Baikal during the last 23000 years , 2000 .

[9]  H. Schulz,et al.  Correlation between Arabian Sea and Greenland climate oscillations of the past 110,000 years , 1998 .

[10]  M. Shimaraev,et al.  Processes of deep‐water renewal in Lake Baikal , 1997 .

[11]  H. Barnes,et al.  Pyrite formation in an anoxic estuarine basin , 1997 .

[12]  D. Imboden,et al.  Description of stability and neutrally buoyant transport in freshwater lakes , 1996 .

[13]  D. Williams,et al.  Continental climate response to orbital forcing from biogenic silica records in Lake Baikal , 1995, Nature.

[14]  G. Bond,et al.  Iceberg Discharges into the North Atlantic on Millennial Time Scales During the Last Glaciation , 1995, Science.

[15]  Vadim A. Kravchinsky,et al.  A rock-magnetic record from Lake Baikal, Siberia: Evidence for Late Quaternary climate change , 1994 .

[16]  A. A. Zhdanov,et al.  Deep ventilation of Lake Baikal waters due to spring thermal bars , 1993 .

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

[18]  G. Fryer.  Comparative aspects of adaptive radiation and speciation in Lake Baikal and the great rift lakes of Africa , 1991, Hydrobiologia.

[19]  E. Carmack,et al.  Deep-water renewal and biological production in Lake Baikal , 1991, Nature.

[20]  R. Berner,et al.  Pyrite formation in euxinic and semi-euxinic sediments , 1985 .

[21]  J. Hilton,et al.  Formation of pyrite in freshwater sediments: Implications for C/S ratios , 1985 .

[22]  R. Berner.  Sedimentary pyrite formation: An update , 1984 .

[23]  R. Berner.  Burial of organic carbon and pyrite sulfur in the modern ocean : its geochemical and environmental significance , 1982 .

[24]  K. Minoura,et al.  Forest-desert alternation history revealed by the pollen-record in lake baikal over the past 5 million years , 2000 .

[25]  T. Takamatsu,et al.  14 - Elemental composition of short sediment cores and ferromanganese concretions from Lake Baikal , 2000 .

[26]  L. M. Galkin,et al.  Nonlinear stability near the temperature of maximum density and thermobaric instability in lake baikal during summer stratification , 2000 .

[27]  G. Kuhn,et al.  Calibration and application of marine sedimentary physical properties using a multi-sensor core logger , 1997 .

[28]  F. P E E T E R S,et al.  Modeling Transport Rates in Lake Baikal : Gas Exchange and Deep Water Renewal , 1997 .

[29]  Douglas F. Williams.  Continuous paleoclimate record recovered for last 5 million years , 1997 .

[30]  S. Colman,et al.  Biogenic Silica in Lake Baikal Sediments: Results From 1990–1992 American Cores , 1994 .

[31]  K. Takai,et al.  Autotrophic picoplankton in southern Lake Baikal: abundance, growth and grazing mortality during summer , 1994 .

[32]  J. D. Hays,et al.  The orbital theory of Pleistocene climate : Support from a revised chronology of the marine δ^ O record. , 1984 .

[33]  J. Leventhal.  An interpretation of carbon and sulfur relationships in Black Sea sediments as indicators of environments of deposition , 1983 .