title: Geochemical partitioning of lead in biogenic carbonate sediments in a coral reef depositional environment.
abstract: The fate of trace elements in reef depositional environments has not been extensively investigated. The aim of this study was to determine the partitioning of Pb in sediments of the Veracruz Reef System, and its relation to local environmental sources. Lead was determined in four geochemical fractions: exchangeable (3.8±0.4μgg-1), carbonate (57.0±13.6μgg-1), organic matter (2.0±0.9μgg-1), and mineral (17.5±5.4μgg-1). For the mineral fraction, lead concentrations were higher in those reefs influenced by river discharge or by long-distance transport of terrigenous sediments. The bioavailable concentration of lead (range: 21.9-85.6μgg-1) indicates that the Veracruz Reef System is a moderately polluted area. As expected, the carbonate fraction contained the highest proportion of Pb (70%), and because the reef framework is largely made up of by biogenic carbonate sediments, hence, it is therefore the most important repository of Pb in coral reef depositional environments.
authors.affiliation: Universidad Nacional Autónoma de México, Facultad de Estudios Superiores Iztacala, UBIPRO, Av. de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, México 54090, Mexico. Electronic address: horta@unam.mx.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Horta-Puga
mesh_terms: D002254:Carbonates; D057894:Coral Reefs; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D008800:Mexico
chemical_list: D002254:Carbonates; D007854:Lead
keywords: Gulf of Mexico; Sediment geochemistry; Sequential extraction; Trace-element partitioning; Veracruz