A GLACIAÇÃO STURTIANA (~750 MA), A ESTRUTURA DO RIFTE MACAÚBAS-SANTO ONOFRE E A ESTRATIGRAFIA DO GRUPO MACAÚBAS, FAIXA ARAÇUAÍ
AbstractThis paper is a contribution to the knowledge of the Sturtian glaciation (~800-750 Ma) and the gravitationalsedimentation of the Macaúbas and Santo Onofre Groups. The primary goal of this paper is: (1) todescribe glaciogenic deposits on the eastern edge of the São Francisco craton; (2) to present stratigraphic,sedimentologic and the tectonic setting of the Macaúbas-Santo Onofre rift. An extensional phase is markedby the intrusion of mafic dike swarms at 1100 – 900 Ma and alkaline rocks (750-670 Ma). The Sturtianglacial event (800-750 Ma), with formation of ice-caps in Rodinia supercontinent, is well exposed in theJequitaí area. Glaciomarine facies developed on the border of the craton grade laterally into debris-flowand turbidites. The Neoproterozoic Macaúbas – Santo Onofre rift evolved into a wide embayment limitedby normal faults and a transfer zone. The sedimentary sequence consists of the diamictites, conglomerates,sandstones,, graywackes, pelites deposited by sediment gravity flows. The Neoproterozoic Macaúbas Grouprepresents rift to drift sedimentation related to the break-up of Rodinia. Macaúbas- Santo Onofre rift isregarded as intracontinental with a limited oceanization located at southern of the basin.
Download data is not yet available.
The copyrights of the works published in Geonomos are those of the author, with rights of first publication for the journal.