17 research outputs found
The Formation of Authigenic Carbonates at a Methane Seep Site in the Northern Part of the Laptev Sea
Authigenic carbonates from cold seeps are unique archives for studying environmental conditions, including biogeochemical processes associated with methane-rich fluid migration through the sediment column. The aim of this research was to study major oxide, mineralogical, and stable isotopic compositions of cold-seep authigenic carbonates collected in the northern part of the Laptev Sea. These carbonates are represented by Mg-calcite with an Mg content of 2% to 8%. The ?13C values range from ?27.5β° to ?28.2β° Vienna Peedee belemnite (VPDB) and indicate that carbonates formed due to anaerobic oxidation of methane, most likely thermogenic in origin. The authigenic pyrite in Mg-calcite is evidence of sulfate reduction during carbonate precipitation. The ?18O values of carbonates vary from 3.5β° to 3.8β° VPDB. The calculated ?18Ofluid values show that pore water temperature for precipitated Mg-calcite was comparable to bottom seawater temperature. The presence of authigenic carbonate in the upper horizons of sediments suggests that the sulfateβmethane transition zone is shallowly below the sedimentβwater interface
Sonar Estimation of Methane Bubble Flux from Thawing Subsea Permafrost: A Case Study from the Laptev Sea Shelf
Seeps found offshore in the East Siberian Arctic Shelf may mark zones of degrading subsea permafrost and related destabilization of gas hydrates. Sonar surveys provide an effective tool for mapping seabed methane fluxes and monitoring subsea Arctic permafrost seepage. The paper presents an overview of existing approaches to sonar estimation of methane bubble flux from the sea floor to the water column and a new method for quantifying CH4 ebullition. In the suggested method, the flux of methane bubbles is estimated from its response to insonification using the backscattering cross section. The method has demonstrated its efficiency in the case study of single- and multi-beam acoustic surveys of a large seep field on the Laptev Sea shelf
Signatures of Molecular Unification and Progressive Oxidation Unfold in Dissolved Organic Matter of the Ob-Irtysh River System along Its Path to the Arctic Ocean
The Ob-Irtysh River system is the seventh-longest one in the world. Unlike the other Great Siberian rivers, it is only slightly impacted by the continuous permafrost in its low flow. Instead, it drains the Great Vasyugan mire, which is the world largest swamp, and receives huge load of the Irtysh waters which drain the populated lowlands of the East Siberian Plain. The central challenge of this paper is to understand the processes responsible for molecular transformations of natural organic matter (NOM) in the Ob-Irtysh river system along the South-North transect. For solving this task, the NOM was isolated from the water samples collected along the 3,000?km transect using solid-phase extraction. The NOM samples were further analyzed using high resolution mass spectrometry and optical spectroscopy. The obtained results have shown a distinct trend both in molecular composition and diversity of the NOM along the South-North transect: the largest diversity was observed in the Southern βswamp-wetlandβ stations. The samples were dominated with humic and lignin-like components, and enriched with aminosugars. After the Irtysh confluence, the molecular nature of NOM has changed drastically: it became much more oxidized and enriched with heterocyclic N-containing compounds. These molecular features are very different from the aliphatics-rich permafrost NOM. They witnesses much more conservative nature of the NOM discharged into the Arctic by the Ob-Irtysh river system. In general, drastic reduction in molecular diversity was observed in the northern stations located in the lower Ob flow
Settings of current sedimentation on the underwater slope of Buor-Khaya bay (Laptev sea)
Nowadays, the Arctic shelf is of increasing interest due to its large reserves of hydrocarbons and other mineral resources. Meanwhile, current knowledge about the processes occurring in the Arctic is still extremely inadequate. There is still not enough data on natural processes within permafrost, which raises many problems and discussions around regional issues. Therefore, new scientific information can further promote the study of the Arctic nature. This study was aimed to identify the specific features of sedimentation and organic matter transformation in the coastal zone of the Arctic seas based on long-term observations. The objects of the study are suspended matter and bottom sediments, including organic carbon content (Corg) and its isotope composition as markers of lithodynamics of the modern depositional environment. Bottom sediments samples were investigated for grain-size composition, organic carbon content and isotopic composition. Furthermore, spatio-temporal variability of the suspended matter distribution in the water column was estimated. Conclusions: for the ice-free period, there are two typical stable turbidity maxima with a suspended matter content ranging from 6,5 to 594 mg/l. Towards the continental slope, the replacement of sandy-aleuritic sediments with clays of continental slope, avandelt bottom, and thermoabrasive-accumulative terrace is accompanied by an increase in organic carbon values from 0,4 to 5,4 % with winter values ranging from 0,6 to 9,3 %. Isotopic composition of organic carbon in the bottom sediments varied from -27,9 to -22,7
Settings of current sedimentation on the underwater slope of Buor-Khaya bay (Laptev sea)
Π Π½Π°ΡΡΠΎΡΡΠ΅Π΅ Π²ΡΠ΅ΠΌΡ ΠΈΠ½ΡΠ΅ΡΠ΅Ρ ΠΊ Π°ΡΠΊΡΠΈΡΠ΅ΡΠΊΠΎΠΌΡ ΡΠ΅Π»ΡΡΡ Π±ΡΡΡΡΠΎ ΡΡΠΈΠ»ΠΈΠ²Π°Π΅ΡΡΡ Π²ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅ Π΅Π³ΠΎ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ Π½Π° ΡΠ³Π»Π΅Π²ΠΎΠ΄ΠΎΡΠΎΠ΄Π½ΠΎΠ΅ ΡΡΡΡΠ΅ ΠΈ Π΄ΡΡΠ³ΠΈΠ΅ ΠΌΠΈΠ½Π΅ΡΠ°Π»ΡΠ½ΡΠ΅ ΡΠ΅ΡΡΡΡΡ. ΠΠ΅ΠΆΠ΄Ρ ΡΠ΅ΠΌ ΡΡΠΎΠ²Π΅Π½Ρ Π·Π½Π°Π½ΠΈΠΉ ΠΎ ΠΏΡΠΎΡΠ΅ΡΡΠ°Ρ
, ΠΏΡΠΎΡΠ΅ΠΊΠ°ΡΡΠΈΡ
Π² Π°ΡΠΊΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠ΅, Π΅ΡΠ΅ ΠΊΡΠ°ΠΉΠ½Π΅ Π½Π΅Π΄ΠΎΡΡΠ°ΡΠΎΡΠ΅Π½. ΠΠΎ ΡΠΈΡ
ΠΏΠΎΡ ΡΡΡΠ΅ΡΡΠ²ΡΠ΅Ρ Π΄Π΅ΡΠΈΡΠΈΡ Π΄Π°Π½Π½ΡΡ
ΠΎ ΠΏΡΠΈΡΠΎΠ΄Π½ΡΡ
ΠΏΡΠΎΡΠ΅ΡΡΠ°Ρ
Π² ΠΊΡΠΈΠΎΠ»ΠΈΡΠΎΠ·ΠΎΠ½Π΅, ΡΡΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ΅Ρ Π΄ΠΈΡΠΊΡΡΡΠΈΠΎΠ½Π½ΡΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ ΡΠ΅ΡΠ΅Π½ΠΈΡ ΠΌΠ½ΠΎΠ³ΠΈΡ
ΡΠ΅Π³ΠΈΠΎΠ½Π°Π»ΡΠ½ΡΡ
ΠΏΡΠΎΠ±Π»Π΅ΠΌ. Π ΡΠ°ΠΊΠΎΠΉ ΠΎΠ±ΡΡΠ°Π½ΠΎΠ²ΠΊΠ΅ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ Π»ΡΠ±ΠΎΠΉ Π½ΠΎΠ²ΠΎΠΉ Π½Π°ΡΡΠ½ΠΎΠΉ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΈ Π²Π½ΠΎΡΠΈΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΡΠΉ Π²ΠΊΠ»Π°Π΄ Π² ΠΏΠΎΠ·Π½Π°Π½ΠΈΠ΅ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΏΡΠΈΡΠΎΠ΄Ρ ΠΡΠΊΡΠΈΠΊΠΈ. Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ: Π²ΡΡΠ²Π»Π΅Π½ΠΈΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠ΅ΠΉ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΎΡΠ°Π΄ΠΊΠΎΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΠΈ Π²Π΅ΡΠ΅ΡΡΠ²Π° Π² Π±Π΅ΡΠ΅Π³ΠΎΠ²ΠΎΠΉ Π·ΠΎΠ½Π΅ Π°ΡΠΊΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΌΠΎΡΠ΅ΠΉ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² ΠΌΠ½ΠΎΠ³ΠΎΠ»Π΅ΡΠ½ΠΈΡ
Π½Π°Π±Π»ΡΠ΄Π΅Π½ΠΈΠΉ. ΠΠ±ΡΠ΅ΠΊΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ: Π²Π·Π²Π΅ΡΠ΅Π½Π½ΡΠΉ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π» ΠΈ Π΄ΠΎΠ½Π½ΡΠ΅ ΠΎΡΠ°Π΄ΠΊΠΈ, Π²ΠΊΠ»ΡΡΠ°Ρ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ³Π»Π΅ΡΠΎΠ΄Π° (Π‘ΠΎΡΠ³) ΠΈ Π΅Π³ΠΎ ΠΈΠ·ΠΎΡΠΎΠΏΠ½ΡΠΉ ΡΠΎΡΡΠ°Π² - ΠΊΠ°ΠΊ ΠΌΠ°ΡΠΊΠ΅ΡΡ Π»ΠΈΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ ΡΡΠ΅Π΄Ρ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΎΡΠ°Π΄ΠΊΠΎΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ. ΠΠ·ΡΡΠ°Π»ΠΈΡΡ Π³ΡΠ°Π½ΡΠ»ΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΈΠΉ (ΡΠ°Π·ΠΌΠ΅ΡΠ½ΡΠΉ) ΡΠΎΡΡΠ°Π² Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ², ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ ΠΈ ΠΈΠ·ΠΎΡΠΎΠΏΠ½ΡΠΉ ΡΠΎΡΡΠ°Π² ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ³Π»Π΅ΡΠΎΠ΄Π°, ΠΎΡΠ΅Π½ΠΈΠ²Π°Π»ΡΡ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎ-Π²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ ΠΈΠ·ΠΌΠ΅Π½ΡΠΈΠ²ΠΎΡΡΠΈ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ Π²Π·Π²Π΅ΡΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° Π² Π²ΠΎΠ΄Π½ΠΎΠΉ ΡΠΎΠ»ΡΠ΅. ΠΡΠ²ΠΎΠ΄Ρ: Π΄Π»Ρ Π±Π΅Π·Π»Π΅Π΄Π½ΠΎΠ³ΠΎ ΠΏΠ΅ΡΠΈΠΎΠ΄Π° ΡΠΈΠΏΠΈΡΠ½Ρ Π΄Π²Π° ΡΡΡΠΎΠΉΡΠΈΠ²ΡΡ
ΠΌΠ°ΠΊΡΠΈΠΌΡΠΌΠ° ΠΌΡΡΠ½ΠΎΡΡΠΈ Ρ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ΠΌ Π²Π·Π²Π΅ΡΠΈ Π² ΠΎΡ 6,5 Π΄ΠΎ 594 ΠΌΠ³/Π». Π Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΠΈ ΠΎΡ ΠΏΠΎΠ±Π΅ΡΠ΅ΠΆΡΡ ΠΊ ΡΠ²Π°Π»Ρ Π³Π»ΡΠ±ΠΈΠ½ Π·Π°ΠΌΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΏΠ΅ΡΡΠ°Π½ΠΎ-Π°Π»Π΅Π²ΡΠΈΡΠΎΠ²ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ² ΠΈΠ»Π°ΠΌΠΈ ΡΠ°ΡΠΈΠΉ ΡΠ²Π°Π»Π° Π³Π»ΡΠ±ΠΈΠ½, ΠΏΠΎΠ΄Π½ΠΎΠΆΡΡ Π°Π²Π°Π½Π΄Π΅Π»ΡΡΡ ΠΈ ΡΠ΅ΡΠΌΠΎΠ°Π±ΡΠ°Π·ΠΈΠΎΠ½Π½ΠΎ-Π°ΠΊΠΊΡΠΌΡΠ»ΡΡΠΈΠ²Π½ΠΎΠΉ ΡΠ΅ΡΡΠ°ΡΡ ΡΠΎΠΏΡΠΎΠ²ΠΎΠΆΠ΄Π°Π΅ΡΡΡ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ΠΌ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ³Π»Π΅ΡΠΎΠ΄Π° ΠΎΡ 0,4 Π΄ΠΎ 5,4 % ΠΏΡΠΈ Π·ΠΈΠΌΠ½ΠΈΡ
Π·Π½Π°ΡΠ΅Π½ΠΈΡΡ
0,6-9,3 %. ΠΠ·ΠΎΡΠΎΠΏΠ½ΡΠΉ ΡΠΎΡΡΠ°Π² ΡΠ³Π»Π΅ΡΠΎΠ΄Π° ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²Π΅ΡΠ΅ΡΡΠ²Π° Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ² Π²Π°ΡΡΠΈΡΠΎΠ²Π°Π» ΠΎΡ -27,9 Π΄ΠΎ -22,7 %.Nowadays, the Arctic shelf is of increasing interest due to its large reserves of hydrocarbons and other mineral resources. Meanwhile, current knowledge about the processes occurring in the Arctic is still extremely inadequate. There is still not enough data on natural processes within permafrost, which raises many problems and discussions around regional issues. Therefore, new scientific information can further promote the study of the Arctic nature. This study was aimed to identify the specific features of sedimentation and organic matter transformation in the coastal zone of the Arctic seas based on long-term observations. The objects of the study are suspended matter and bottom sediments, including organic carbon content (Corg) and its isotope composition as markers of lithodynamics of the modern depositional environment. Bottom sediments samples were investigated for grain-size composition, organic carbon content and isotopic composition. Furthermore, spatio-temporal variability of the suspended matter distribution in the water column was estimated. Conclusions: for the ice-free period, there are two typical stable turbidity maxima with a suspended matter content ranging from 6,5 to 594 mg/l. Towards the continental slope, the replacement of sandy-aleuritic sediments with clays of continental slope, avandelt bottom, and thermoabrasive-accumulative terrace is accompanied by an increase in organic carbon values from 0,4 to 5,4 % with winter values ranging from 0,6 to 9,3 %. Isotopic composition of organic carbon in the bottom sediments varied from -27,9 to -22,7
Discovery and characterization of submarine groundwater discharge in the Siberian Arctic seas: A case study in Buor-Khaya Gulf, Laptev Sea
It has been suggested that increasing freshwater discharge to the Arctic Ocean may also occur as submarine groundwater discharge (SGD), yet there are no direct observations of this phenomenon in the Arctic shelf seas. This study tests the hypothesis that SGD does exist in the Siberian-Arctic shelf seas but its dynamics may be largely controlled by complicated geocryological conditions such as permafrost. The field-observational approach in the southeast Laptev Sea used a combination of hydrological (temperature, salinity), geological (bottom sediment drilling, geoelectric surveys) and geochemical (224Ra, 223Ra and 222Rn) techniques. Active SGD was documented in the vicinity of the Lena River delta with two different operational modes. In the first system, groundwater discharges through tectonogenic permafrost talik zones was registered in both wintertime and summertime seasons. The second SGD mechanism was cryogenic squeezing out of brine and water-soluble salts detected on the periphery of ice hummocks in the wintertime season. The proposed mechanisms of groundwater transport and discharge in the arctic land-shelf system is elaborated. Through salinity versus 224Ra and 224Ra/223Ra diagrams, the three main SGD-influenced water masses were identified and their end-member composition was constrained. Further studies should apply these techniques to a broader scale with the objective to reach an estimate of the relative importance of the SGD transport vector relative to surface freshwater discharge for both the water balance and aquatic components such as dissolved organic carbon, carbon dioxide, methane, and nutrients
Lithological features of surface sediment and their influence on organic m atter distribution across the East-Siberian Arctic shelf
The Arctic is undergoing rapid climate change, which affects the global and regional carbon cycles. The East Siberian Arctic shelf, that is believed to store huge amounts of organic carbon in different pools, has been the subject of growing scientific interest in recent decades. The aim of the work was to study the lithological features of bottom sediments on the East Siberian Arctic shelf and to assess their influence on the spatial distribution of organic material in the study area. Materials and methods. The sediment samples were collected during the 45-day multidisciplinary SWERUS-C3 expedition on IB ODEN in summer 2014. Surface sediments from inner and middle East Siberian Arctic shelf were collected in summer 2008 during the International Siberian Shelf Study (ISSS-08) campaign onboard the HV Yakob Smirnitsky. The samples were analyzed for the grain size and specific surface area characteristics and total organic carbon content. It is shown that the subglacial sedimentation and the accumulation of predominantly fine-grained sediments prevail within the study area. Nevertheless, atypical sand zones were identified on the outer shelf. The authors have suggested several external factors, including modern and paleo ice scouring in the early Holocene, and intensive gas venting, which are accompanied by removal of fine-grained sediments. The paper considers spatial distribution of organic matter in the bottom sediments of the East Siberian Arctic shelf and its interrelation with their lithological properties
Geochemical specific of sediments at methane cold seep site on the Laptev Sea outer shelf
ΠΠΊΡΡΠ°Π»ΡΠ½ΠΎΡΡΡ. Π₯Π°ΡΠ°ΠΊΡΠ΅ΡΠ½ΠΎΠΉ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΡΡ ΡΠ΅Π»ΡΡΠ° ΠΌΠΎΡΡ ΠΠ°ΠΏΡΠ΅Π²ΡΡ
ΡΠ²Π»ΡΠ΅ΡΡΡ Π½Π°Π»ΠΈΡΠΈΠ΅ ΡΡΠ°ΡΡΠΊΠΎΠ² ΠΌΠ°ΡΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠ°Π·Π³ΡΡΠ·ΠΊΠΈ ΠΌΠ΅ΡΠ°Π½-ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ»ΡΠΈΠ΄ΠΎΠ² Ρ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ ΠΌΠΎΡΡΠΊΠΎΠ³ΠΎ Π΄Π½Π° Π² Π²ΠΎΠ΄Π½ΡΡ ΡΠΎΠ»ΡΡ - ΠΌΠ΅ΡΠ°Π½ΠΎΠ²ΡΡ
ΡΠΈΠΏΠΎΠ². ΠΠ»ΡΡΠ΅Π²ΡΠΌΠΈ Π±ΠΈΠΎΠ³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ°ΠΌΠΈ, ΠΏΡΠΎΡΠ΅ΠΊΠ°ΡΡΠΈΠΌΠΈ ΠΏΡΠΈ ΠΌΠΈΠ³ΡΠ°ΡΠΈΠΈ ΠΌΠ΅ΡΠ°Π½Π° ΡΠ΅ΡΠ΅Π· ΠΎΡΠ°Π΄ΠΎΡΠ½ΡΡ ΡΡΠ΅Π΄Ρ, ΡΠ²Π»ΡΡΡΡΡ Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠ΅ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΠ΅ ΠΌΠ΅ΡΠ°Π½Π° ΠΈ Π±Π°ΠΊΡΠ΅ΡΠΈΠ°Π»ΡΠ½Π°Ρ ΡΡΠ»ΡΡΠ°ΡΡΠ΅Π΄ΡΠΊΡΠΈΡ. ΠΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΡΡΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΎΠΊΠΈΡΠ»ΠΈΡΠ΅Π»ΡΠ½ΠΎ-Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΡΠ΅Π΄ΠΈΠΌΠ΅Π½ΡΠ°ΡΠΈΠΈ, ΡΡΠΎ Π²Π»ΠΈΡΠ΅Ρ Π½Π° Π±ΠΈΠΎΠ³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠΈΠΊΠ»Ρ ΡΡΠ΄Π° ΡΠ΅Π΄ΠΎΠΊΡ-ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ². Π¦Π΅Π»Ρ: ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ Π²Π»ΠΈΡΠ½ΠΈΡ ΠΏΡΠΎΡΠ°ΡΠΈΠ²Π°ΡΡΠΈΡ
ΡΡ ΠΌΠ΅ΡΠ°Π½-ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ»ΡΠΈΠ΄ΠΎΠ² Π½Π° Π³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠΈΠΊΠ»Ρ ΠΆΠ΅Π»Π΅Π·Π°, ΡΠ³Π»Π΅ΡΠΎΠ΄Π° ΠΈ Π½Π΅ΠΊΠΎΡΠΎΡΡΡ
ΡΠ΅Π΄ΠΎΠΊΡ-ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ². ΠΠ±ΡΠ΅ΠΊΡ. ΠΡΠ»ΠΈ ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Ρ Π΄Π°Π½Π½ΡΠ΅ ΠΎ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡΡ
ΡΠ³Π»Π΅ΡΠΎΠ΄Π°, ΠΆΠ΅Π»Π΅Π·Π°, ΠΈ ΡΡΠ΄Π° ΡΠ΅Π΄ΠΎΠΊΡ-ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² (Mn, Co, Ni, Cu, Zn, Cr, Ba, Mo, U) Π² ΡΡΠ΅Ρ
ΠΊΠ΅ΡΠ½Π°Ρ
Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ², ΠΎΡΠΎΠ±ΡΠ°Π½Π½ΡΡ
Π½Π° Π²Π½Π΅ΡΠ½Π΅ΠΌ ΡΠ΅Π»ΡΡΠ΅ ΠΌΠΎΡΡ ΠΠ°ΠΏΡΠ΅Π²ΡΡ
. ΠΠ²Π° ΠΈΠ· ΡΡΠ΅Ρ
ΠΊΠ΅ΡΠ½ΠΎΠ² ΠΏΠΎΠ»ΡΡΠ΅Π½Ρ Π½Π° ΡΡΠ°ΡΡΠΊΠ°Ρ
Ρ Π·Π°ΡΠ΅Π³ΠΈΡΡΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠ°Π·Π³ΡΡΠ·ΠΊΠΎΠΉ ΠΌΠ΅ΡΠ°Π½-ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ»ΡΠΈΠ΄ΠΎΠ² ΠΈ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π»ΠΈΡΡ Π² ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ ΠΎΡΠ°Π΄ΠΊΠΎΠ², ΠΏΠΎΠ΄Π²Π΅ΡΠΆΠ΅Π½Π½ΡΡ
Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠΌΡ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΡ ΠΌΠ΅ΡΠ°Π½Π°. ΠΠ΅ΡΠΎΠ΄Ρ: ΠΏΠΈΡΠΎΠ»ΠΈΠ· (Rock-Eval 6 Turbo, Vinci Technologies), ΡΠ΅Π½ΡΠ³Π΅Π½ΠΎΡΠ»ΡΠΎΡΠ΅ΡΡΠ΅Π½ΡΠ½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· (HORIBA X-Ray Analytical Microscope XGT 7200), ΠΌΠ°ΡΡ-ΡΠΏΠ΅ΠΊΡΡΠΎΠΌΠ΅ΡΡΠΈΡ Ρ ΠΈΠ½Π΄ΡΠΊΡΠΈΠ²Π½ΠΎ-ΡΠ²ΡΠ·Π°Π½Π½ΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΠΎΠΉ (ΠΠ‘Π-ΠΠ‘, ELAN DRC-e). Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ. Π‘ΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ TOC ΠΈ Fe Π² Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠ°Ρ
Π½Π΅ ΠΎΡΡΠ°ΠΆΠ°ΡΡ Π²Π»ΠΈΡΠ½ΠΈΡ Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠ³ΠΎ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΡ Π½Π° ΠΈΡ
Π³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠΈΠΊΠ»Ρ ΠΈ ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΡΡΡΡ ΡΠΏΠ΅ΡΠΈΡΠΈΠΊΠΎΠΉ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎΠ³ΠΎ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΏΠΎΡΠΎΠΊΠΎΠ² ΠΎΡΠ°Π΄ΠΎΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π°. ΠΠΎ Π²ΡΠ΅Ρ
ΠΈΠ·ΡΡΠ΅Π½Π½ΡΡ
ΠΊΠ΅ΡΠ½Π°Ρ
ΠΎΡΠΌΠ΅ΡΠ°ΡΡΡΡ ΠΏΠΎΠ²ΡΡΠ΅Π½Π½ΡΠ΅ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΠΈ Mn, ΠΏΡΠΈΡΡΠΎΡΠ΅Π½Π½ΡΠ΅ ΠΊ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠΌΡ Π³ΠΎΡΠΈΠ·ΠΎΠ½ΡΡ ΠΎΡΠ°Π΄ΠΊΠΎΠ². ΠΠ° ΡΡΠ°ΡΡΠΊΠ°Ρ
ΡΠ°Π·Π³ΡΡΠ·ΠΊΠΈ ΠΌΠ΅ΡΠ°Π½Π° ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΡΠΉ ΡΠ»ΠΎΠΉ Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ² Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΠ΅ΡΡΡ ΠΎΠ±ΠΎΠ³Π°ΡΠ΅Π½ΠΈΠ΅ΠΌ Mo, Ni ΠΈ Cr. ΠΠ·Π±ΠΈΡΠ°ΡΠ΅Π»ΡΠ½ΠΎΠ΅ ΠΎΠ±ΠΎΠ³Π°ΡΠ΅Π½ΠΈΡ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ ΠΎΡΠ°Π΄ΠΊΠΎΠ² Π½Π΅ΠΊΠΎΡΠΎΡΡΠΌΠΈ ΡΠ΅Π΄ΠΎΠΊΡ-ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΠΌΠΈ ΡΠ»Π΅ΠΌΠ΅Π½ΡΠ°ΠΌΠΈ ΠΌΠΎΠΆΠ΅Ρ Π±ΡΡΡ Π²ΡΠ·Π²Π°Π½ΠΎ ΠΌΠΈΠ³ΡΠ°ΡΠΈΠ΅ΠΉ ΠΌΠ΅ΡΠ°Π½-ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ»ΡΠΈΠ΄ΠΎΠ², ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΡΡΠΈΡ
ΠΏΠ΅ΡΠ΅Π½ΠΎΡΡ ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² Π² ΡΠ°ΡΡΠ²ΠΎΡΠ΅Π½Π½ΠΎΠΉ ΡΠΎΡΠΌΠ΅ ΠΈΠ· Π±ΠΎΠ»Π΅Π΅ Π³Π»ΡΠ±ΠΎΠΊΠΈΡ
Π³ΠΎΡΠΈΠ·ΠΎΠ½ΡΠΎΠ². Π‘ΠΎΡΠ±ΡΠΈΡ ΡΡΠΈΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠΌ Π²Π΅ΡΠ΅ΡΡΠ²ΠΎΠΌ ΠΈ ΠΎΠΊΠΈΡΠ»Π°ΠΌΠΈ/Π³ΠΈΠ΄ΡΠΎΠΊΠΈΡΠ»Π°ΠΌΠΈ Fe-Mn, ΠΏΠΎ-Π²ΠΈΠ΄ΠΈΠΌΠΎΠΌΡ, ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΊΠ»ΡΡΠ΅Π²ΡΠΌ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠΌ, ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΡΡΠΈΠΌ ΠΎΡΠ°ΠΆΠ΄Π΅Π½ΠΈΠ΅ Mo, Ni ΠΈ Cr.Relevance. A specific feature of the Laptev Sea shelf is the sites of discharge of methane-containing fluids from the surface of the seabed into the water column (methane cold seeps). The key biogeochemical processes occurring during methane migration through the sedimentary environment are anaerobic oxidation of methane and bacterial sulfate reduction. The activity of these processes encourages a change in the redox conditions of sedimentation, which affects the biogeochemical cycles of some redox-sensitive elements. The aim of the research is to study the influence of methane-containing fluids on the geochemical cycles of iron, carbon and some redox-sensitive elements. Objects. The data of the concentrations of carbon, iron, and some of redox-sensitive elements (Mn, Co, Ni, Cu, Zn, Cr, Ba, Mo, U) in three bottom sediment cores sampled on the outer shelf of the Laptev Sea were analyzed. Two of the three cores were obtained at methane cold seep sites and were considered as sediments subject to anaerobic methane oxidation. Methods: pyrolysis (Rock-Eval 6 Turbo, Vinci Technologies), X-Ray analysis (HORIBA X-Ray Analytical Microscope XGT 7200), Inductively coupled plasma mass spectrometry (ICP-MS, ELAN DRC-e). Results. TOC and Fe contents in sediments do not reflect the impact of anaerobic oxidation on their geochemical cycles and controlled by the specifics of the spatial distribution of sedimentary material. In all the studied cores, there are elevated Mn concentrations confined to the surface layer of sediments. At methane cold seep sites, the surface layer of bottom sediments is characterized by enrichment in Mo, Ni and Cr. The selective enrichment of the surface layer of sediments with some redox-sensitive elements can be caused by the migration of methane-containing fluids, which facilitate the transport of elements in dissolved form from deeper horizons. The sorption of these elements by organic matter and Fe-Mn oxihydroxides appears to be the key mechanism controlling the deposition of Mo, Ni, and Cr
Methane seepage impact on authigenic pyrite morphology in sediments of the Laptev Sea continental slope
ΠΠΊΡΡΠ°Π»ΡΠ½ΠΎΡΡΡ. Π ΡΠ°Π±ΠΎΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΠ·ΡΡΠ΅Π½ΠΈΡ ΠΌΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΈ ΡΠ°Π·ΠΌΠ΅ΡΠΎΠ² Π°ΡΡΠΈΠ³Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΠΈΡΠΈΡΠ°, ΠΏΡΠΈΡΡΡΡΡΠ²ΡΡΡΠ΅Π³ΠΎ Π² Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠ°Ρ
ΠΊΠ°ΠΊ Π² ΡΠ°ΡΡΠ΅ΡΠ½Π½ΠΎΠΌ Π²ΠΈΠ΄Π΅, ΡΠ°ΠΊ ΠΈ Π² Π°ΡΡΠΎΡΠΈΠ°ΡΠΈΠΈ Ρ ΠΊΠ°ΡΠ±ΠΎΠ½Π°ΡΠ½ΡΠΌΠΈ ΡΡΡΠΆΠ΅Π½ΠΈΡΠΌΠΈ. Π‘ ΠΏΠΎΠ·ΠΈΡΠΈΠΈ ΠΈΠ·ΡΡΠ΅Π½ΠΈΡ ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΡΠ°Π½Π½Π΅Π³ΠΎ Π΄ΠΈΠ°Π³Π΅Π½Π΅Π·Π° Π°ΡΡΠΈΠ³Π΅Π½Π½ΡΠΉ ΠΏΠΈΡΠΈΡ ΡΡΠΈΡΠ°Π΅ΡΡΡ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π²Π°ΠΆΠ½ΡΠΌ ΡΡΠ»ΡΡΠΈΠ΄Π½ΡΠΌ ΠΌΠΈΠ½Π΅ΡΠ°Π»ΠΎΠΌ ΠΆΠ΅Π»Π΅Π·Π° ΠΏΠΎ ΠΏΡΠΈΡΠΈΠ½Π΅ Π΅Π³ΠΎ Π½Π°ΠΈΠ±ΠΎΠ»ΡΡΠ΅ΠΉ Π΄ΠΈΠ°Π³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΡΡΠΈ ΠΎΡΠ½ΠΎΡΠΈΡΠ΅Π»ΡΠ½ΠΎ Π΄ΡΡΠ³ΠΈΡ
ΡΡΠ»ΡΡΠΈΠ΄ΠΎΠ² ΠΆΠ΅Π»Π΅Π·Π°. Π Π°Π½Π΅Π΅ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½Π½ΡΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΡΠΈΡΠ»Π΅Π½Π½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΌΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΈ ΡΠ°Π·ΠΌΠ΅ΡΠΎΠ² Π°ΡΡΠΈΠ³Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΠΈΡΠΈΡΠ° ΠΏΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠΎΠΉ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΈ Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΎΠΊΠΈΡΠ»ΠΈΡΠ΅Π»ΡΠ½ΠΎ-Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΠΎΡΠ°Π΄ΠΊΠΎΠ½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΡ ΠΈ ΡΠ°Π½Π½Π΅Π³ΠΎ Π΄ΠΈΠ°Π³Π΅Π½Π΅Π·Π° ΠΊΠ°ΠΊ Π² ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
, ΡΠ°ΠΊ ΠΈ Π² Π΄ΡΠ΅Π²Π½ΠΈΡ
ΠΎΡΠ°Π΄ΠΎΡΠ½ΡΡ
Π±Π°ΡΡΠ΅ΠΉΠ½Π°Ρ
. Π¦Π΅Π»ΡΡ ΡΠ°Π±ΠΎΡΡ ΡΠ²Π»ΡΠ»ΠΎΡΡ ΠΈΠ·ΡΡΠ΅Π½ΠΈΡ ΠΌΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈ ΡΠ°Π·ΠΌΠ΅ΡΠ½ΡΡ
Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ Π°ΡΡΠΈΠ³Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΠΈΡΠΈΡΠ° Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ Π²Π»ΠΈΡΠ½ΠΈΡ ΡΡΠ»ΡΡΠ°Ρ-ΡΠΏΡΠ°Π²Π»ΡΠ΅ΠΌΠΎΠ³ΠΎ Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠ³ΠΎ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΡ ΠΌΠ΅ΡΠ°Π½Π° Π½Π° ΡΡΠ»ΠΎΠ²ΠΈΡ ΡΠ°Π½Π½Π΅Π³ΠΎ Π΄ΠΈΠ°Π³Π΅Π½Π΅Π·Π°. ΠΠ΅ΡΠΎΠ΄Ρ: Π³ΠΈΠ΄ΡΠΎΠ°ΠΊΡΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ (Kongsberg EA600), ΡΠ΅Π½ΡΠ³Π΅Π½ΠΎΠ΄ΠΈΡΡΠ°ΠΊΡΠΈΠΎΠ½Π½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· (Bruker D2 Phaser), ΡΠΊΠ°Π½ΠΈΡΡΡΡΠ°Ρ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½Π°Ρ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΡ Ρ Π»ΠΎΠΊΠ°Π»ΡΠ½ΡΠΌ ΡΠ½Π΅ΡΠ³ΠΎΠ΄ΠΈΡΠΏΠ΅ΡΡΠΈΠΎΠ½Π½ΡΠΌ Π°Π½Π°Π»ΠΈΠ·ΠΎΠΌ (TESCAN VEGA 3 SBU). ΠΡΠ½ΠΎΠ²Π½ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ. Π ΠΌΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΌ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΈ ΠΏΠΈΡΠΈΡ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ ΠΈΠ΄ΠΈΠΎΠΌΠΎΡΡΠ½ΡΠΌΠΈ ΠΈ Π³ΠΈΠΏΠΈΠ΄ΠΈΠΎΠΌΠΎΡΡΠ½ΡΠΌΠΈ ΠΊΡΠΈΡΡΠ°Π»Π»Π°ΠΌΠΈ, ΡΡΠ°ΠΌΠ±ΠΎΠΈΠ΄Π°ΠΌΠΈ ΠΈ ΠΈΡ
ΡΠΊΠΎΠΏΠ»Π΅Π½ΠΈΡΠΌΠΈ, ΡΠ°Π΄ΠΈΠ°Π»ΡΠ½ΡΠΌΠΈ Π½Π°ΡΠΎΡΡΠ°ΠΌΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΡΠ΅ΡΠΆΠ½Π΅Π²ΠΈΠ΄Π½ΡΠΌΠΈ Π°Π³ΡΠ΅Π³Π°ΡΠ°ΠΌΠΈ. Π‘ΡΠ΅Π΄Π½ΠΈΠΉ Π΄ΠΈΠ°ΠΌΠ΅ΡΡ ΡΡΠ°ΠΌΠ±ΠΎΠΈΠ΄ΠΎΠ², Π° ΡΠ°ΠΊΠΆΠ΅ Π²ΡΡΠΎΠΊΠΎΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΡΡΠ°Π½Π΄Π°ΡΡΠ½ΠΎΠ³ΠΎ ΠΎΡΠΊΠ»ΠΎΠ½Π΅Π½ΠΈΡ Π² ΠΎΠ±Π΅ΠΈΡ
ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅ΠΌΡΡ
Π²ΡΠ±ΠΎΡΠΊΠ°Ρ
ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΠ΅Ρ ΠΎ Π΄ΠΈΠ°Π³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΠΏΡΠΎΠΈΡΡ
ΠΎΠΆΠ΄Π΅Π½ΠΈΠΈ ΠΏΠΈΡΠΈΡΠ°. Π‘ΡΠ»ΡΡΠ°Ρ-ΡΠΏΡΠ°Π²Π»ΡΠ΅ΠΌΠΎΠ΅ Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠ΅ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΠ΅ ΠΌΠ΅ΡΠ°Π½Π° ΡΠ²Π»ΡΠ΅ΡΡΡ Π΄ΠΎΠΌΠΈΠ½ΠΈΡΡΡΡΠΈΠΌ ΠΏΡΠΎΡΠ΅ΡΡΠΎΠΌ, ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΡΡΠΈΠΌ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΡΡΠ»ΡΡΠΈΠ΄ΠΎΠ² ΠΆΠ΅Π»Π΅Π·Π°, ΡΡΠΎ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°Π΅ΡΡΡ Π½Π°Π»ΠΈΡΠΈΠ΅ΠΌ Π΄ΠΎΡΡΠ°ΡΠΎΡΠ½ΠΎ ΠΊΡΡΠΏΠ½ΡΡ
ΡΡΠ°ΠΌΠ±ΠΎΠΈΠ΄ΠΎΠ² Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠΎΠΌ Π΄ΠΎ 49 ΠΌΠΊΠΌ. ΠΠ°Π±Π»ΡΠ΄Π°Π΅ΠΌΠΎΠ΅ ΡΠ°Π·Π½ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ ΠΌΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠΎΡΠΌ ΠΏΠΈΡΠΈΡΠ° ΠΌΠΎΠΆΠ΅Ρ ΠΎΡΡΠ°ΠΆΠ°ΡΡ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π΄ΠΈΠ°Π³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΠ΅Π΄Ρ Ρ ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ΠΌ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ, Π²ΡΠ·Π²Π°Π½Π½ΠΎΠ΅ Π²Π°ΡΠΈΠ°ΡΠΈΠ²Π½ΠΎΡΡΡΡ ΠΏΠΎΡΠΎΠΊΠ° ΠΌΠ΅ΡΠ°Π½-ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ»ΡΠΈΠ΄ΠΎΠ².Relevance. The paper presents the results of studying the morphology and size distribution of authigenic pyrite, both present in sediments and in carbonate nodules. From the point of view of studying the conditions of early diagenesis, authigenic pyrite is considered the most important iron sulfide mineral due to its greatest diagenetic stability relative to other iron sulfides. Numerous previous studies of the morphology and size of authigenic pyrite show the possibility of using this information to assess the redox conditions of sedimentation and early diagenesis in both modern and ancient sedimentary basins. The aim of the research was to study the morphology and size distribution of authigenic pyrite to assess the effect of sulfate-controlled anaerobic oxidation of methane on the conditions of early diagenesis. Methods: field hydroacoustic researches (Kongsberg EA600), X-ray diffraction (Bruker D2 Phaser), scanning electron microscopy with local energy dispersive analysis (TESCAN VEGA 3 SBU). Results. Morphologically, pyrite is represented by idiomorphic and hypidiomorphic crystals, framboids and their clusters, radial outgrowths, and also rod like aggregates. The mean diameter of framboids, as well as the high value of standard deviation, indicate the diagenetic origin of pyrite. Sulfate-driven anaerobic oxidation of methane is the dominant process that controls the formation of iron sulfides, which is confirmed by the presence of fairly large framboids up to 49 ΞΌm in diameter. The observed diversity of pyrite morphology may reflect the change in the diagenetic environment over time, due to the variability of the flow of methane-bearing fluids
Authigenic minerals in the bottom sediments from seeps of the Laptev Sea
ΠΠ΅ΡΠ°Π½ΠΎΠ²ΡΠ΅ ΡΠΈΠΏΡ ΡΠ²Π»ΡΡΡΡΡ ΡΠΈΡΠΎΠΊΠΎ ΡΠ°ΡΠΏΡΠΎΡΡΡΠ°Π½Π΅Π½Π½ΡΠΌ ΡΠ²Π»Π΅Π½ΠΈΠ΅ΠΌ, Π½Π°Π±Π»ΡΠ΄Π°Π΅ΠΌΡΠΌ Π½Π° ΡΠ΅Π»ΡΡΠ°Ρ
ΠΈ ΠΊΠΎΠ½ΡΠΈΠ½Π΅Π½ΡΠ°Π»ΡΠ½ΡΡ
ΡΠΊΠ»ΠΎΠ½Π°Ρ
Π²Π½ΡΡΡΠ΅Π½Π½ΠΈΡ
ΠΈ ΠΎΠΊΡΠ°ΠΈΠ½Π½ΡΡ
ΠΌΠΎΡΠ΅ΠΉ ΠΏΠΎ Π²ΡΠ΅ΠΌΡ ΠΌΠΈΡΡ, Π² ΡΠΎΠΌ ΡΠΈΡΠ»Π΅ ΠΈ Π² ΠΌΠΎΡΠ΅ ΠΠ°ΠΏΡΠ΅Π²ΡΡ
. ΠΠ»ΡΡΠ΅Π²ΡΠΌΠΈ Π±ΠΈΠΎΠ³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ°ΠΌΠΈ, ΠΏΡΠΎΡΠ΅ΠΊΠ°ΡΡΠΈΠΌΠΈ Π² Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠ°Ρ
ΡΡΠΈΡ
ΡΠ°ΠΉΠΎΠ½ΠΎΠ², ΡΠ²Π»ΡΡΡΡΡ Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠ΅ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΠ΅ ΠΌΠ΅ΡΠ°Π½Π° Π² ΡΠΎΡΠ΅ΡΠ°Π½ΠΈΠΈ Ρ Π±Π°ΠΊΡΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ ΡΡΠ»ΡΡΠ°ΡΡΠ΅Π΄ΡΠΊΡΠΈΠ΅ΠΉ. ΠΠ±Π° ΡΡΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΡΠ° ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΡΡ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠΏΠ΅ΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π°ΡΡΠΈΠ³Π΅Π½Π½ΠΎΠΉ ΠΌΠΈΠ½Π΅ΡΠ°Π»ΠΈΠ·Π°ΡΠΈΠΈ. Π¦Π΅Π»ΡΡ Π½Π°ΡΡΠΎΡΡΠ΅ΠΉ ΡΠ°Π±ΠΎΡΡ ΡΠ²Π»ΡΠ»ΠΎΡΡ ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ Π°ΡΡΠΈΠ³Π΅Π½Π½ΡΡ
ΠΌΠΈΠ½Π΅ΡΠ°Π»ΠΎΠ² Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ² Ρ Π°Π½ΠΎΠΌΠ°Π»ΡΠ½ΠΎ Π²ΡΡΠΎΠΊΠΈΠΌΠΈ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡΠΌΠΈ ΠΌΠ΅ΡΠ°Π½Π°, ΠΎΡΠΎΠ±ΡΠ°Π½Π½ΡΡ
Π½Π° Π΄Π²ΡΡ
ΡΠΈΠΏΠΎΠ²ΡΡ
ΡΡΠ°ΡΡΠΊΠ°Ρ
Π² ΡΠ΅Π²Π΅ΡΠΎ-Π²ΠΎΡΡΠΎΡΠ½ΠΎΠΉ ΡΠ°ΡΡΠΈ ΠΌΠΎΡΡ ΠΠ°ΠΏΡΠ΅Π²ΡΡ
, Π΄Π»Ρ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΏΡΠΈΠ·Π½Π°ΠΊΠΎΠ² ΠΈΡ
ΠΈΠ΄Π΅Π½ΡΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ Π² Π΄ΡΠ΅Π²Π½ΠΈΡ
ΠΎΡΠ°Π΄ΠΎΡΠ½ΡΡ
ΠΏΠΎΡΠΎΠ΄Π°Ρ
. ΠΡΠΈΠ²Π΅Π΄Π΅Π½Ρ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ Π»ΠΈΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈ ΠΌΠΈΠ½Π΅ΡΠ°Π»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ². ΠΡΠ»ΠΎ ΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΎΡΠ½ΠΎΠ²Π½ΡΠΌΠΈ Π°ΡΡΠΈΠ³Π΅Π½Π½ΡΠΌΠΈ ΠΌΠΈΠ½Π΅ΡΠ°Π»Π°ΠΌΠΈ Π² ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Π½ΡΡ
ΠΎΠ±ΡΠ°Π·ΡΠ°Ρ
Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ², ΠΎΡΠΎΠ±ΡΠ°Π½Π½ΡΡ
Ρ Π΄Π²ΡΡ
ΡΠΈΠΏΠΎΠ²ΡΡ
ΡΡΠ°ΡΡΠΊΠΎΠ² Π² ΡΠ΅Π²Π΅ΡΠΎ-Π²ΠΎΡΡΠΎΡΠ½ΠΎΠΉ ΡΠ°ΡΡΠΈ ΠΌΠΎΡΡ ΠΠ°ΠΏΡΠ΅Π²ΡΡ
, ΡΠ²Π»ΡΡΡΡΡ ΠΌΠ°Π³Π½Π΅Π·ΠΈΠ°Π»ΡΠ½ΡΠΉ ΠΊΠ°Π»ΡΡΠΈΡ, Π³ΠΈΠΏΡ ΠΈ ΠΏΠΈΡΠΈΡ. Π Π°Π·Π½Π°Ρ ΡΠΏΠ΅ΡΠΈΡΠΈΠΊΠ° Π°ΡΡΠΈΠ³Π΅Π½Π½ΠΎΠΉ ΠΌΠΈΠ½Π΅ΡΠ°Π»ΠΈΠ·Π°ΡΠΈΠΈ, ΠΏΡΠ΅Π΄ΠΏΠΎΠ»ΠΎΠΆΠΈΡΠ΅Π»ΡΠ½ΠΎ, ΡΠΊΠ°Π·ΡΠ²Π°Π΅Ρ Π½Π° ΡΠ°Π·Π»ΠΈΡΠΈΡ Π² ΡΠ΅ΠΆΠΈΠΌΠ°Ρ
ΠΌΠΈΠ³ΡΠ°ΡΠΈΠΈ ΠΌΠ΅ΡΠ°Π½-ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ»ΡΠΈΠ΄ΠΎΠ² Π½Π° ΡΡΠΈΡ
ΡΡΠ°ΡΡΠΊΠ°Ρ
. ΠΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠ΅ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠΈ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ°ΡΠΈΠ²Π°Π½ΠΈΡ ΠΌΠ΅ΡΠ°Π½Π° Π² ΠΏΡΠ΅Π΄Π΅Π»Π°Ρ
Β«Π²ΠΎΡΡΠΎΡΠ½ΠΎΠ³ΠΎ ΡΠΈΠΏΠ°Β» ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΠΎΠ²Π°Π»ΠΎ Π½Π°ΡΡΡΠ΅Π½ΠΈΡ ΠΏΠΎΡΠΎΠ²ΠΎΠΉ Π²ΠΎΠ΄Ρ ΠΈΠΎΠ½Π°ΠΌΠΈ SO[4]{2-} ΠΈ Ca{2+} ΠΈ, ΠΊΠ°ΠΊ ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅, ΠΎΡΠ°ΠΆΠ΄Π΅Π½ΠΈΡ Π³ΠΈΠΏΡΠ°. ΠΠ»ΠΈΠ·ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ΅ ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΠ΅ ΡΡΠ»ΡΡΠ°Ρ-ΠΌΠ΅ΡΠ°Π½ΠΎΠ²ΠΎΠΉ ΡΡΠ°Π½Π·ΠΈΡΠ½ΠΎΠΉ Π·ΠΎΠ½Ρ Π² Β«Π·Π°ΠΏΠ°Π΄Π½ΠΎΠΌ ΡΠΈΠΏΠ΅Β», ΠΎΠ±ΡΡΠ»ΠΎΠ²Π»Π΅Π½Π½ΠΎΠ΅ Π²ΡΡΠΎΠΊΠΈΠΌΠΈ ΠΏΠΎΡΠΎΠΊΠ°ΠΌΠΈ ΠΌΠ΅ΡΠ°Π½Π°, Π±Π»Π°Π³ΠΎΠΏΡΠΈΡΡΡΡΠ²ΠΎΠ²Π°Π»ΠΎ ΠΎΡΠ°ΠΆΠ΄Π΅Π½ΠΈΡ ΠΌΠ°Π³Π½Π΅Π·ΠΈΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΊΠ°Π»ΡΡΠΈΡΠ° Π² Π²Π΅ΡΡ
Π½ΠΈΡ
Π³ΠΎΡΠΈΠ·ΠΎΠ½ΡΠ°Ρ
Π΄ΠΎΠ½Π½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ². ΠΡΠΈΡΡΡΡΡΠ²ΠΈΠ΅ ΠΏΠΈΡΠΈΡΠ° Π² ΠΎΡΠ°Π΄ΠΊΠ°Ρ
ΠΊΠ°ΠΊ Π²ΠΎΡΡΠΎΡΠ½ΠΎΠ³ΠΎ, ΡΠ°ΠΊ Π·Π°ΠΏΠ°Π΄Π½ΠΎΠ³ΠΎ ΡΠΈΠΏΠΎΠ²ΡΡ
ΡΡΠ°ΡΡΠΊΠΎΠ² ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΠΎΠΌ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ° Π±Π°ΠΊΡΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ ΡΡΠ»ΡΡΠ°Ρ-ΡΠ΅Π΄ΡΠΊΡΠΈΠΈ ΠΏΡΠΈ Π°Π½Π°ΡΡΠΎΠ±Π½ΠΎΠΌ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΠΈ ΠΌΠ΅ΡΠ°Π½Π°.Methane seeps is a widespread phenomenon observed on the shelves and continental slopes of inland and border seas around the world, including the Laptev Sea. Key biogeochemical processes occurring in the bottom sediments of these areas are the anaerobic oxidation of methane in combination with bacterial sulfate reduction. Both of these processes control the formation of specific autigenic mineralization. The aim of this work was to study authigenic minerals of bottom sediments with abnormally high concentrations of methane taken from two seeps in the north-eastern part of the Laptev Sea to determine the signs of their identification in ancient sedimentary rocks. The paper presents the results of lithological and mineralogical studies of bottom sediments. It was found that magnesium calcite, gypsum and pyrite are the main authigenic minerals in the studied samples of bottom sediments taken from two seeps in the north-eastern part of the Laptev Sea. The different specifics of authigenic mineralization indicate differences in conditions of migration of methane-containing fluids in these areas, presumably. Temporary decrease in the rate of methane seepage within the Β«eastern seepΒ» contributed to the saturation of pore water with SO[4]{2-} and Ca{2+} and, as a consequence, gypsum deposition. The near-surface position of the sulfate-methane transition zone in the Β«western seepΒ» due to high methane flows favored the precipitation of magnesian calcite in the upper horizons of bottom sediments. The presence of pyrite in sediments of eastern and western seep is evidence of the activity of the bacterial sulfate reduction during anaerobic methane oxidation