Correlations of some Neoproterozoic carbonate-dominated successions in South America based on high-resolution chemostratigraphy

Alcides Nobrega Sial, Claudio Gaucher, Aroldo Misi, Paulo Cesar Boggiani, Carlos José Souza de Alvarenga, Valderez Pinto Ferreira, Marcio Martins Pimentel, José Augusto Pedreira, Lucas Verissimo Warren, Rodrigo Fernández-Ramírez, Mauro Geraldes, Natan Silva Pereira (+2 others)
2016 Brazilian Journal of Geology  
ABSTRACT: This report reviews and incorporates new elemental and isotope chemostratigraphic data for correlation of Neoproterozoic carbonate-dominated successions in South America (Argentina, Bolivia, Brazil, Paraguay and Uruguay). These thick mixed carbonate/siliciclastic successions were largely deposited in epicontinental basins or accumulated on passive margins on the edges of cratons (e.g. São Francisco, Amazonia, Rio Apa Block, Pampia and Río de la Plata paleocontinents) during
more » ... ) during extensional events related to the rifting of the Rodinia Supercontinent. From the stratigraphic point of view, these successions occur as three mega-sequences: glaciogenic, marine carbonate platform (above glaciomarine diamictites or rift successions), and dominantly continental to transitional siliciclastics. In the orogenic belts surrounding cratons, carbonate-dominated successions with important volcanoclastic/siliciclastic contribution have been, in most cases, strongly deformed. The precise ages of these successions remain a matter of debate, but recently new paleontological and geochronological data have considerably constrained depositional intervals. Here, we report high-resolution C, O, Sr, and S isotope trends measured in well-preserved sample sets and mainly use Sr and C isotopes in concert with lithostratigraphic/biostratigraphic observations to provide detailed correlations of these successions. The establishing of a high-level and definite chemostratigraphic correlation between Neoproterozoic basins in South America is the main goal of this work.
doi:10.1590/2317-4889201620160079 fatcat:43msawhyqrdtxempfm72imywvy