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Sediments at marine methane seep sites provide potential archives of past fluid flow that serve to explore seepage activities over time. Three gravity cores (D-8, D-F, and D-7) were collected from seep sites on the northern slope of the South China Sea where gas hydrates were drilled in the subsurface. Various carbon and sulfur contents, δ 13 C values of total inorganic carbon (δ 13 C TIC ), δ 34 S values of chromium reducible sulfur (δ 34 S CRS ), trace element contents, grain size, and AMS 14 C dating of planktonic Foraminifera in the sediments were determined to explore the availability of related proxies at seeps and to trace past methane seepage activities. Evidence for the presence of methane seepage and consequently anaerobic oxidation of methane comes from the occurrence of 13 C-depleted authigenic carbonate nodules (δ 13 C values as low as −49‰) discovered at an interval of 150–200 cm in core D-7. This finding is supported by high S/C ratios and molybdenum enrichment in the same interval. However, low contents of CRS and negative δ 34 S CRS values are present. It is suggested to reflect a transient methane seepage event, which continued for about 1 ka based on the 14 C ages. Cores D-8 and D-F have δ 13 C TIC values close to zero, low S/C ratios and CRS contents, negative δ 34 S CRS values, and no trace element enrichment, suggesting a negligible impact of methane-seepage on the sediments. The negative δ 34 S CRS values of the studied seep-impacted and background sediments suggest that the application of δ 34 S CRS alone as a proxy to identify AOM-related process may be insufficient. Sediment carbon-sulfur-trace element systematics and 14 C ages used here have the potential to be a promising tool to recognize transient methane seepages and constrain their timescales. [ABSTRACT FROM AUTHOR]