This study presents results of the petrographic, mineralogical, stable isotopes of oxygen and carbon, and trace element investigation of authigenic carbonates collected at newly discovered active cold seeps on the Laptev Sea continental slope at ~300 m water depth. These carbonates are mainly represented by Mg-calcite with MgCO₃ content from 9.1 mol% to 14.0 mol%. The low δ¹³C values of carbonates ranging from −50.6 ‰ to −32.4 ‰ (V-PDB) indicate that they were formed from anaerobic oxidation of biogenic methane and minor participation of other carbon sources. The difference between measured (from 4.7 ‰ to 5.5 ‰) and calculated (4.0 ‰) δ¹⁸O_carb values might be inherited from fluids enriched in ¹⁸O due to dissociation of gas hydrates, which could be the source of methane. The carbonates exhibit weak enrichment in Co, moderate and strong enrichments in As, Mo, and Sb, and strong enrichment in U. Interestingly, As, Sb, and Co correlate with the pyrite content. This indicates that authigenic iron sulfides promote the immobilization of these redox-sensitive elements in seep sediments. The (Mo/U)_EF values and anomalies of concentration of Mo and U probably indicate variations in the redox conditions during carbonate formation due to episodically seepage activity changes. Ascending methane-bearing fluids were the main contributor to the enrichment of cold-seep carbonates in As, Mo, Sb, and U at the Laptev Sea continental slope. However additional input from the particulate shuttle process can not be ruled out.

本研究介绍了在拉普捷夫海陆坡约 300 米水深处新发现的活跃冷泉收集的自生碳酸盐的岩石学、矿物学、稳定同位素和微量元素调查的结果。这些碳酸盐主要以MgCO ₃含量为9.1～14.0 mol%的镁方解石为代表。碳酸盐的低δ ¹³ C 值在-50.6 ‰ 到-32.4 ‰ (V-PDB) 范围内表明它们是由生物甲烷的厌氧氧化和其他碳源的少量参与形成的。测量的（从 4.7 ‰ 到 5.5 ‰）和计算的（4.0 ‰）δ ¹⁸ O _carb值之间的差异可能来自富含^18的流体O 由于天然气水合物的分解，这可能是甲烷的来源。碳酸盐中 Co 的富集较弱，As、Mo 和 Sb 的富集程度中等和强，而 U 的富集程度较高。有趣的是，As、Sb 和 Co 与黄铁矿含量相关。这表明自生硫化铁促进了这些氧化还原敏感元素在渗流沉积物中的固定。(Mo/U)_英孚Mo 和 U 的浓度值和异常值可能表明在碳酸盐形成过程中，由于渗流活动的变化，氧化还原条件发生了变化。上升的含甲烷流体是拉普捷夫海陆坡冷渗碳酸盐在 As、Mo、Sb 和 U 中富集的主要贡献者。然而，不能排除来自微粒穿梭过程的额外输入。