2019-09-052019-09-052013TEIXEIRA, Marília Carvalho. Estudo mineralógico e geoquímico dos sedimentos da região compreendida entre a Foz do rio Araguari e os Cinturões Lacustres, na Zona Costeira do estado do Amapá. Orientador: José Francisco Berrêdo Reis da Silva. Coorientador: Rômulo Simões Angélica. 2013. 99 f. Trabalho de Curso (Bacharelado em Geologia) - Faculdade de Geologia, Instituto de Geociências, Universidade Federal do Pará, Belém, 2013. Disponível em: http://bdm.ufpa.br/jspui/handle/prefix/2016. Acesso em:.http://bdm.ufpa.br/jspui/handle/prefix/2016The tertiary and quaternary sediments of the region between the mouth of the Rio Araguari and Belts Lacustres in the state of Amapá, comprising sands, silty sands, silts and sandy silts. Mineralogically consist of quartz (56%), muscovite (18%), albite (6%), K-feldspar (trace) and clay as well as oxides and hydroxides of iron and heavy mineral transparent and opaque. The clay minerals are composed of smectite (53%), kaolinite (33%) and illite (14%), and chlorite in trace amounts. Among the transparent heavy minerals were identified 13 distinct species, represented by three major associations: assemblies A (epidote-hornblende-hypersthene-diopside-garnet) and B (epidote-zircon-hornblende-tourmaline) correspond to the fine sediments of Quaternary and indicate influence of source area of predominantly mafic-ultramafic composition and also felsic igneous and sedimentary; the content of the assembly C (zircon-epidote-tourmaline-staurolite-hornblende), referring to the coarser sediments of Tertiary indicates influences by source area of mainly felsic composition, as well as sedimentary rocks, mafic and yet so secondary. CIA values show that both tertiary sediments (> 90) as the quaternary (75-85) were affected by high weathering conditions, being more pronounced in the samples of Quaternary. The depletion in La, Th, Sc and Hf, and higher content of Co in the Quaternary sediments reflects the high concentration of ferromagnesian minerals (assemblies A and B) and its derivation from rocks of the Andes and sediment Solimões Basin. Tertiary samples, however, have more enriched composition of La, Th, Hf and Zr, indicating abundant mineral ltraestables (assembly C), as well as derivation from felsic more sources of Precambrian Shield sand recycled sediments from the Amazon Basin, mixed in various proportions. Therefore, variations in the distribution of minerals and chemical elements in the tertiary and quaternary sediments are related to two main factors: hydraulic fractionation during transport and influence of source areas of different composition.Acesso AbertoMineralogiaGeoquímica de sedimentosProveniênciaZona Costeira do AmapáCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::MINERALOGIATrabalho de Curso - Graduação - Monografia