A variety of biochemical and chemical effects occur in natural gas seepage areas. Microorganisms that use methane as energy can form microbial mats and even microbial reefs and micrite mounds that are several meters high [9, 14, 24-27]. Macro-bodied organisms such as dense swarms of shrimp, mussels, clams, gastropods and tube worms may also appear [12, 28, 29, 30, 56, 57, 70]. These organisms use methane and its oxides as energy sources and are often characterized by populations with high abundance and low diversity. Since methane hydrates are rich in Ba2+ ions [31, 32], their addition will form hole-filling barite [33] and layered barite deposition in the methane leakage area. Under aerobic conditions, methane is oxidized by aerobic microorganisms (aerobic methane oxidation), producing CO2 (CH4+O2→CO2+2H2O) [34]. CO2 derived from methane can dissolve carbonate (CaCO3+CO2+H2O→2HCO-3+Ca2+), leading to local carbonate dissolution and low pH conditions [35], delaying carbonate precipitation and enlarging pores, Rupture occurs. Under anaerobic conditions, due to the action of sulfate reducing bacteria, methane undergoes anoxic oxidation to form biological carbonates and monosulfides (2HCO-3+Ca2+→CaCO3+CO2+H2O) [36]. The local supersaturation of biological carbonates produced by methane can enhance carbonate precipitation (2HCO-3+Ca2+→CaCO3+CO2+H2O), forming clot-like microcrystalline limestone, radial and botryoidal aragonite cements [29 , 37～39, 40～42]. That is, cold seep carbonate rocks are formed. Supersaturated HS- also enhances pyrite precipitation, often in the form of strawberry. Methane is the substance with the lowest δ13C value in nature, with an average of about -60‰ [34, 43, 44]. Therefore, both CO2 produced by aerobic methane oxidation and biological carbonates produced by anoxic methane oxidation have abnormally low δ13C values ??[45-47]. Cold seep carbonate rock deposits are important signs of seafloor natural gas seepage systems and important evidence indicating the possible existence of natural gas hydrates.