Author(s)

Rúbia Ribeiro Viana, Gislaine Amorés Battilani

Department of Mineral Resource, Federal University of Mato Grosso, Cuiabá, Brazil.

The Monte Santo Alkaline Intrusive Suite (MSAIS) is an association syenite foid, nepheline syenite and syenite, which are intruded in metapelites of the Rio do Coco meta-volcanic-sedimentary Sequence, presenting abundant pegmathoid veins cutting all of them. The ages obtained by Shrimp (1051 ± 22 Ma, 1048 ± 11 Ma) are very close those younger age obtained by U-Pb laser ablation (1056 ± 21), beeing interpreted as crystallization age. These dating reveal also that MSAIS rocks were affected by common succession of younger events below 550 Ma ago, responsible by the later rocky bodies of varying composition occurring in the region, including the alkaline pegmatites hosted in the nepheline syenite of the MSAIS.

Alkaline Rocks, Shrimp Dating, Tocantins Structural Province, Neoproterozoic, Brazil

Viana, R. and Battilani, G. (2014) SHRIMP U-Pb and U-Pb Laser Ablation Geochronological on Zircons from Monte Santo Alkaline Intrusive Suite, Westhern Araguaia Belt, Tocantins State, Brazil. Journal of Geoscience and Environment Protection, 2, 170-180. doi: 10.4236/gep.2014.23022.