Coupling between 210Pbex and organic matter in sediments of a nutrient-enriched lake: An example from Lake Chenghai, China

210Pb as a tool for establishing sediment chronologies: examples of potentials and limitations of conventional dating models

“…Near-coastal sediments often are characterized by high variability of their grain size distributions. It is known that heavy metals and radionuclides including excess 210 Pb and 137 Cs are enriched in fine-grained sediment compared to coarse particles (Smith and Walton, 1980;Chanton et al, 1983;Cundy and Croudace, 1995) and organic matter (Wan et al, 2005). This effect is caused by the higher cation exchange capacities of fine-grained (especially clay) minerals and of organic matter compared to quartz.…”

Sedimentary record of PAHs in the Barigui River and its relation to the socioeconomic development of Curitiba, Brazil

“…PAHs of pyrolytic origin are attributed to the incomplete combustion of fossil organic matter at high temperatures (Yunker et al, 2002). By contrast, petrogenic PAHs are produced when organic matter is matured over geological time through a geothermal gradient (Wan et al, 2005). The contribution of PAHs derived by microbial activity is considered small and has not yet been fully described (Bzdusek et al, 2004;Opuene et al, 2007;Soclo et al, 2000).…”

Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems: setting the record straight

“…While tidal marsh and mangrove sediments have relatively high organic matter content (on average 25%) (Breithaupt et al, 2012;Cochran et al, 1998), mineral deposits account for the majority (>85%) of the accumulated substrate in seagrass sediments (Koch, 2001;Mazarrasa et al, 2015) (Table 1). Excess 210 Pb has a strong affinity for surface particles of fine sediments (Chanton et al, 1983;Cundy and Croudace, 1995;He and Walling, 1996a) and organic matter (Wan et al, 2005), thus any changes in these parameters due to sediment redistribution processes or to natural heterogeneity may also 30 result in unique types of 210 Pb concentration profiles in sediment cores of vegetated coastal ecosystems, adding complexity to the determination of sediment model age and sedimentation rates.…”