The circulation of South American precious metals in Brazil at the end of the 17th century

“…Sharp increases of flux and EFs before 1900 may indicate mining waste in the waterway, while a recent Al normalized flux increase in Laranjeiras is likely the result of increased fine grained sediment runoff. [24][25][26] We argue that fluxes and EFs are a much better indicator of anthropogenic influences over time in areas of dynamic sedimentation, as these calculations account for dilution caused by the overall sediment load or even anthropogenic anomalies associated to specific pollutants. 53 Here we show that in assessing the overall metal impact of trace metal pollution to coastal sediments, flux rates and EFs are invaluable when compiling data on metal contamination processes and/or establishing background values associated to the sediment load (e.g.…”

Section: Discussionmentioning

confidence: 99%

“…24 Gold mining also occurred here during European colonization. [25][26][27] Upstream erosion and wastewater from these activities delivers increased particulate matter to the mangroves, and can result in increased deposition of trace metal contaminants. 10 In fact, agricultural activity has caused mercury (Hg) contamination of sediments within the Curitiba.…”

mentioning

confidence: 99%

Influence of Anthropogenic Activities on Trace Metal Accumulation in Brazilian Mangrove Sediments

Conrad

Sanders

2017

Rev. Virtual Quim.

View full text Add to dashboard Cite

Resumo: Dois testemunhos de sedimento foram coletados em margem de manguezais para estudar os efeitos de atividades antrópicas na região de Paranaguá, no Brasil. Conteúdos, fluxos e fatores de enriquecimento (FE) de metais-traço foram calculados. Os conteúdos de metais-traço (Hg, Zn, Pb, Ni, Co, Mn e Cu) variaram ao longo dos testemunhos e entre os dois locais, mas não foram indicativos das taxas de acumulação ou EF. Enriquecimentos leves desses metais foram observados de forma consistente com atividades de mineração na área de estudo, ocorridas antes de 1900. Foram observados múltiplos aumentos das taxas de fluxo. Um deles foi congruente com a atividade de mineração pré-industrial que foi observada em ambos os testemunhos. O outro pico de fluxo só foi detectado em um testemunho, ocorrendo após 1990 e não foi acompanhado por nenhum enriquecimento. Este aumento de fluxo foi devido ao desenvolvimento urbano, causando aumento da deposição de partículas de grãos finos nos manguezais da Baía de Laranjeiras. Além de avaliar os impactos das atividades antrópicas em manguezais desta área, um ponto focal adicional deste trabalho foi mostrar os significados do conteúdo, do fluxo e do FE em estudos sobre poluição de sedimentos costeiros. A validade do uso de dados de fluxo e EF, além dos conteúdos de metais, para discernir tendências de contaminação em sedimentos de mangue é discutida.Palavras-chave: Fatores de enriquecimento; metais pesados; fluxo de metais; desenvolvimento urbano; atividades de mineração; Hg; Zn; Pb; Ni; Co; Mn; Cu. AbstractTwo sediment cores were collected at the margins of well-developed mangrove forests to study the effects of anthropogenic activities in the Paranagua region of Brazil. Calculations of sediment trace metal content, flux, and enrichment factors (EF) were performed. Trace metal (Hg, Zn, Pb, Ni, Co, Mn and Cu) contents showed differing values down core and amongst sites, which were not indicative of metal accumulation rates or EF. Slight enrichments of these metals were observed congruent with mining activities in the area occurring prior to 1900. Multiple rapid increases of flux rates were observed, one congruent with pre-industrial mining activity which was observed in both sediment cores. The other flux spike was only detected in one sediment core, occurring post 1990, and was not accompanied by any enrichment. This increase in flux is believed to be due to upstream urban development causing increased fine grain particle deposition in the mangroves of Laranjeiras Bay. Beyond assessing impacts of anthropogenic activities on mangroves of this area, an additional focal point of this work is to show the significance of content flux and EF in studies concerning coastal sediment pollution research. The validity of using flux and EF data, in addition to metals contents, to discern contamination trends in mangrove sediments is discussed.

show abstract

“…Guerra carried out the study of the circulation of South American gold in Brazil at the end of the 17th century as well (see [107]). PAA and LA-ICP-MS were used to determine the elemental composition in a selection of gold coins issued in Mexico, Peru, Bolivia, Guatemala, Colombia and Chile.…”

Section: Metalsmentioning

confidence: 99%