SciELO - Scientific Electronic Library Online

 
vol.44 número3Maturação permotriássica e os vários estágios de migração de hidrocarbonetos na Formação Assistência (Subgrupo Irati), Bacia do Paraná: implicações para os modelos exploratóriosInfluência de estruturas brasilianas na sismicidade desencadeada por reservatório na Usina Hidrelétrica de Irapé, Minas Gerais, Brasil índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Brazilian Journal of Geology

versão impressa ISSN 2317-4889

Resumo

DUTRA, Alanna C.; MARANGONI, Yára R.  e  TRINDADE, Ricardo I. F.. Aeromagnetic and physical-chemical properties of some complexes from Goiás Alkaline Province. Braz. J. Geol. [online]. 2014, vol.44, n.3, pp.361-373. ISSN 2317-4889.  http://dx.doi.org/10.5327/Z2317-4889201400030003.

The Goiás Alkaline Province (GAP), located on the north edge of the Paraná Basin, has alkaline complexes with strong magnetic signatures. The 3D inversion of magnetic signal was performed on the aeromagnetic data. Since the intrusions present a strong remnant magnetization, as measured in the laboratory, a careful analysis of this component was also realized. The sum vector of the remnant and induced components were used as a virtual induced magnetic field during the 3D inversion process. The geometric parameters were obtained from the quantitative analysis of magnetic data, using Total Gradient Direction and Analytical Signal Phase, performed over magnetic signal reduced to the pole. Magnetic susceptibility and density were measured in laboratory. All this information were used as the initial model in the inversion. The results of 3D inversion show that the alkaline intrusions have roots up to 10-12 km depth. The magnetic susceptibility is distributed in almost spherical and cylindrical shapes. The possibility of spherical shapes arise the hypothesis that the GAP intrusions at the northern part of the province represent magmatic chambers. The alkaline magma ascends from the lithosphere, and used two main fault systems as space for emplacement. These faults systems appear in the magnetic signal analysis as linear magnetic features. Chemical analysis confirmed the alkaline and subalkaline character of the magmas. The high MgO content shows the primitive character of these intrusions but the Ba anomaly indicates a possible crustal contamination.

Palavras-chave : Alkaline magmatism; magnetic data; remnant magnetization; 3D inversion.

        · resumo em Português     · texto em Inglês     · Inglês ( pdf )