Sedimentary provenance in the southern sector of the São Francisco Basin, SE Brazil

Author(s)

de Paula-Santos, Gustavo Macedo ^[1] ; Babinski, Marly ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Geociencias, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: BRAZILIAN JOURNAL OF GEOLOGY; v. 48, n. 1, p. 51-74, JAN-MAR 2018.
• Web of Science Citations: 3

Abstract

ABSTRACT: We present new Sm-Nd, U-Pb and Hf isotope geochronological data for the siliciclastic rocks in the southern sector of the São Francisco Basin. An abrupt change in the Sm-Nd data is observed from the Carrancas Formation’s oligomitic conglomerates (TDM ages between 2.7 and 3.3 Ga; εNd(550 Ma) values between -25.09 and -17.98), its finer facies, and the finer facies of the the Moema Laminite (TDM ages from 1.4 to 2.1 Ga; εNd(550 Ma) values between -9.46 and -5.59). No further significant changes in the Sm-Nd data occur farther upwards in the Bambuí Group (Sm-Nd TDM ages within the 1.3-2.0 Ga interval; εNd(550 Ma) values from -9.53 to -4.09), showing a lack of reorganization in the source areas throughout the deposition of the basin. This is yet another argument to dismiss an unconformity within the Bambuí Group. The presence of the index fossil Cloudina sp. in the lower Sete Lagoas Formation makes the glaciation probably Late Ediacaran in age. U-Pb ages for detrital zircons of the Bambuí Group range from the Archean to the early Ediacaran, but the current data is insufficient to distinguish between the contribution from sources in the Brasília and Araçuaí belts. (AU)

• FAPESP's process: 16/06114-6 - The Neoproterozoic Earth System and the rise of biological complexity
• Grantee: Ricardo Ivan Ferreira da Trindade
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/00399-1 - Chemical weathering and nutrient input into late Ediacaran ocean and their relationship to life diversification
• Grantee: Gustavo Macedo de Paula Santos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral