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The sediment grain-size effect (GSE), a fundamental factor relevant to the interpretation of elemental concentrations and isotopic compositions, has been normalized using conservative elements such as aluminum (Al), cesium (Cs), and lithium (Li) (C ( Al , Cs , Li ) ), which serve as proxies for the natural metal-controlling variables of grain size, mineralogy, and organic matter. However, a secondary GSE reportedly remains even after compensation by the Al-normalization procedure, particularly for the concentrations of transition metals (C T.M ). This secondary effect also occurred in the C ( Li , Cs ) /C Al ratios of the Korean coastal sediments examined in this study. The primary and secondary GSEs on Cs and Li concentrations can be explained by the quartz-dilution effect and the Cs- and Li-incorporation effect of phyllosilicate minerals, respectively, based on a model involving three component end-members: a Cs- and Li-free sand-dominated sediment component consisting mostly of quartz and feldspar, a Cs- and Li-bearing silt-dominated component of mica, and a Cs- and Li-enriched clay-dominated component of illite. Although the primary and secondary GSEs on the concentrations of transition metals (particularly Cu and Ni) in coastal sediments might be normalized by dividing the metal concentrations by the square of the Al concentration (C T.M . /(C Al ) 2 ), the GSEs can also be normalized by dividing the concentrations by the exact Cs (or Li) concentration (C T.M . /C Cs ). [ABSTRACT FROM AUTHOR]

Element concentrations ( C element ) of the sediments in the diverse Korean coastal environments were constrained strongly by the grain-size effect (GSE), especially after compensation for metal-free carbonate and organic material contents. However, the GSE in some elements (especially metallic elements) was not completely offset by conventional Al-normalization ( C element / C Al ratio), and further the best-fit regression lines between the concentrations of Al and elements may not be linear, but instead curved, and also cannot pass through the origin point (0, 0). The results suggest the presence of conventional GSE (primary GSE) as well as another GSE (i.e., secondary GSE), which was well supported by the factor analysis for the variable of C element / C Al ratios. Such primary and secondary GSEs are likely caused by physical and chemical processes, respectively, such as the quartz-dilution effect by metal-free, coarse-grained sediments and diagenetic reactions in organic-rich, fine-grained sediments. Furthermore, these GSEs in Korean coastal sediments can be quantitatively normalized by a quadratic equation: C element = a 0 · C Al + a 1 · ( C Al ) 2 , where a 0 and a 1 are constants for the primary and the secondary GSEs, respectively. [ABSTRACT FROM AUTHOR]