The origin and composition of carbonatite-derived carbonate-bearing fluorapatite deposits

Carbonate-bearing fluorapatite rocks occur at over 30 globally distributed carbonatite complexes and represent a substantial potential supply of phosphorus for the fertiliser industry. However, the process(es) involved in forming carbonate-bearing fluorapatite at some carbonatites remain equivocal, with both hydrothermal and weathering mechanisms inferred. In this contribution, we compare the paragenesis and trace element contents of carbonate-bearing fluorapatite rocks from the Kovdor, Sokli, Bukusu, Catalão I and Glenover carbonatites in order to further understand their origin, as well as to comment upon the concentration of elements that may be deleterious to fertiliser production. The paragenesis of apatite from each deposit is broadly equivalent, comprising residual magmatic grains overgrown by several different stages of carbonate-bearing fluorapatite. The first forms epitactic overgrowths on residual magmatic grains, followed by the formation of massive apatite which, in turn, is cross-cut by late euhedral and colloform apatite generations. Compositionally, the paragenetic sequence corresponds to a substantial decrease in the concentration of rare earth elements (REE), Sr, Na and Th, with an increase in U and Cd. The carbonate-bearing fluorapatite exhibits a negative Ce anomaly, attributed to oxic conditions in a surficial environment and, in combination with the textural and compositional commonality, supports a weathering origin for these rocks. Carbonate-bearing fluorapatite has Th contents which are several orders of magnitude lower than magmatic apatite grains, potentially making such apatite a more environmentally attractive feedstock for the fertiliser industry. Uranium and cadmium contents are higher in carbonate-bearing fluorapatite than magmatic carbonatite apatite, but are much lower than most marine phosphorites

Perfil da vítima atendida pelo serviço pré-hospitalar aéreo de Pernambuco

Estudo do tipo descritivo-exploratório com abordagem quantitativa sobre o perfil da vítima atendida pelo serviço pré-hospitalar aéreo de Pernambuco. As ocorrências foram avaliadas no período de agosto de 2007 a julho de 2008, correspondentes ao primeiro ano de funcionamento do hangar no Recife. Nesse período, foram estudados 283 fichas de ocorrências, com média de 23 atendimentos mensais. Dos vôos, 66% foram de resgate, com 11 minutos de tempo-resposta. Quanto à causa do atendimento, 79% foram por causas externas, na sua maioria de acidentes de trânsito. Prevaleceu o sexo masculino com faixa etária mediana de 34 anos. O resgate dessas vítimas graves deve ser realizado de forma rápida e eficaz, por isso analisou-se a relação da gravidade da vítima com o tempo-resposta