²¹⁰Pb geochronology and trace metal fluxes (Cd, Cu and Pb) in the Gulf of Tehuantepec, South Pacific of Mexico

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• 作者：Ruiz-Fern&aacute ; ndez ; Ana Carolina ; P&aacute ; ez-Osuna ; Federico ; Machain-Castillo ; Marí ; a Luisa ; et. al.
• 关键词：²¹⁰Pb-derived sedimentation rates ; Trace metals accumulation ; Gulf of Tehuantepec
• 刊名：Journal of Environmental Radioactivity
• 出版年：2004
• 出版时间：2004
• 年：2004
• 卷：76
• 期：1-2
• 页码：161-175
• 全文大小：282 K

文摘

Distributions of Al, Cd, Cu, Fe, Li, Mn and Pb were analyzed in a sediment core collected in the Gulf of Tehuantepec, an important fisheries region located in the South Pacific of Mexico, where data on metal accumulation and accretion rates were previously almost nonexistent. Depth profiles of metal concentrations were converted to time-based profiles by using a ²¹⁰Pb-derived vertical accretion rate, estimated to be 0.05 cm year⁻¹ on the average. Sediments were dated up to 8 cm depth, corresponding to a layer of ca. 140 years old. The historical changes of metal accumulation along the sediment core have shown a moderate enrichment of Cd, Cu and Pb concentrations at present, of about threefold the corresponding background concentrations. Chronological trace metal records showed that metal fluxes have increased over the last 20 years, reaching the maximum values at present of 2.5, 22.5 and 45.8 (μg cm⁻² year⁻¹) for Cd, Pb and Cu, respectively. These increments in metal fluxes are likely influenced by the development of anthropogenic land-based activities since over this period of time oil production activities in the region have had a significant development.