Bulk sulfur isotopic data and proxy minerals from the Sete Lagoas Formation (Bambuí Group)

Abstract

The particular mineral association containing barite, apatite and aragonite from the base of the Sete Lagoas Formation (SLF), central São Francisco craton (Brazil), provides a valuable information about the chemical evolution of the marine water during the end of the Neoproterozoic. The occurrence of these proxy minerals for marine sulfate in the lower and middle part of the unit encourages to investigate how the stratigraphic variation of sulfur isotope occur in the Neoproterozoic ocean. This internship project aims to present a high resolution bulk sulfur isotopic data for the Sete Lagoas Formation and discuss its relationship with framboidal and cuboidal pyrites (´34Spy -SIMS) from a chert band in the middle part of the unit. The internship will be developed at the Virginia Tech University (USA), supervised by Prof. Dr. Shuhai Xiao. The motivation for this internship is learning different analytical techniques (mainly S isotopes preparation and analysis, and SIMS analysis) applied to Ediacaran carbonate rocks that contribute to determine the paleoenvironmental conditions using a combination of sedimentology and geochemistry approaches.