| Abstract: | To identify the possible sources and formation mechanism of perylene in sediments, temporal trends of perylene and other polycyclic aromatic hydrocarbons, as well as the organic matters, were analyzed in sediment cores from Dianchi Lake and Sihailongwan Maar Lake in China. Significantly high concentrations of perylene were observed in both cores and increased gradually with the sediment depth. Source identification suggested that perylene in both cores were of primarily diagenetic origin,other than the anthropogenic inputs. Both terrigenous and aquatic organic matters could be the source of perylene in sediments and diagenetic formation of perylene in sediment is kinetically controlled by the microbial activities under anaerobic conditions. All evidence points to the fact that the formation of perylene in sediment should be an index of the microbial activities and environmental conditions, other than the source of specific organic matters or precursors. In addition, we should be cautious when using any geochemical indicators involving the microbial alternation. |
