Structural, petrographic and geochemical characteristics of mafic dikes intrusive in metasedimentary rocks of the Crixás greenstone belt, Goiás

Authors

  • Hardy Jost Universidade de Brasília; Instituto de Geociências; Departamento de Geoquímica e Recursos Minerais
  • Jayme Estevão Scandolara Companhia de Pesquisa de Recursos Minerais; Serviço Geológico do Brasil

DOI:

https://doi.org/10.5327/Z1519-874X2010000300008

Keywords:

Geochemistry, Mafic dikes, Paleoproterozoic, Greenstone belt, Crixás, Goiás

Abstract

Mafic dikes and stocks are a common feature in the Archean terrain of Goiás, Central Brazil, where they occur as swarms of 2.3 - 2.5 Ga within the granite-gneiss complexes (2.8 e 2.7 Ga), as well as intrusions related to the komatiite and basalt flows of the greenstone belts lower stratigraphic units, but were unknown within the upper metasedimentary units. Detailed study of core sections from several drill-sites in the area of the Crixás greenstone belt gold deposits showed that dike intrusion occurred after the main Paleoproterozoic deformation and metamorphism of the metasedimentary units, and literature data indicate that the magmatic zircons from the dikes yielded an age of 2,170 ± 17 Ma. Petrographic and geochemical data show that they have the composition of epicratonic high-Ti diabases, which are similar to the large continental flood basalts of the Paraná Basin. The age of the intrusions may be correlated with the short time-interval of the Rhyacian (2.20 to 2.17 Ga), during which successive localized episodes of mantle plume volcanism occurred on the Earth.

Downloads

Download data is not yet available.

References

Downloads

Published

2010-10-01

Issue

Vol. 10 No. 3 (2010)

Section

Articles

License

Authors who publish in this journal shall comply with the following terms: 

  1. Authors keep their copyright and grant to Geologia USP: Série Científica the right of first publication, with the paper under the Creative Commons BY-NC-SA license (summary of the license: https://creativecommons.org/licenses/by-nc-sa/4.0 | full text of the license: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode) that allows the non-commercial sharing of the paper and granting the proper copyrights of the first publication in this journal.
  2. Authors are authorized to take additional contracts separately, for non-exclusive distribution of the version of the paper published in this journal (publish in institutional repository or as a book chapter), granting the proper copyrights of first publication in this journal.
  3. Authors are allowed and encouraged to publish and distribute their paper online (in institutional repositories or their personal page) at any point before or during the editorial process, since this can generate productive changes as well as increase the impact and citation of the published paper (See The effect of Open Access and downloads on citation impact).

How to Cite

Jost, H., & Scandolara, J. E. (2010). Structural, petrographic and geochemical characteristics of mafic dikes intrusive in metasedimentary rocks of the Crixás greenstone belt, Goiás . Geologia USP. Série Científica, 10(3), 118-134. https://doi.org/10.5327/Z1519-874X2010000300008