Investigation of oxygen levels in the Ediacaran through isotopic chemostratigraphy (C, Sr, Cr, Cd) of the Tamengo Formation-Corumbá Group

• Grant number: 21/02628-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: August 01, 2021
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Paulo César Boggiani
• Grantee: Henrique Albuquerque Fernandes
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 23/02223-9 - Cr-Cd-Sr isotopes and trace elements in Ediacaran carbonates of the Corumbá and Nama groups (Brazil and Namibia): tracking atmospheric oxygenation and paleoproductivity, BE.EP.DD

Abstract

The rise of atmospheric oxygen levels to near present values is still a controversial question. Some geochemical proxies indicate a gradual increase during the Neoproterozoic, while others suggest fluctuations in the levels of atmospheric and marine O2 after 800My, with the main rise only in the Paleozoic. In this context, investigating events of atmospheric oxygenation during the Neoproterozoic is crucial in order to evaluate the different scenarios that link these events and the radiation of metazoans, especially in the Ediacaran-Cambrian limit. This PhD project aims to approach these questions through the paleoenvironmental analysis of the Tamengo Formation (Corumbá Group - Mato Grosso do Sul State, Brazil). For this purpose, Cr isotopes analysis, used as atmospheric paleoredox proxy, will be carried out, together with the traditional isotopic C, O and Sr systems, which will be used to infer the marine redox conditions, changes in primary productivity and the basin connection to the global ocean, and Cd isotopes analysis, which is an useful proxy for levels of primary productivity. This work counts with the partnership of Professor Dr. Robert Frei, from the University of Copenhagen, Denmark, a pioneer in the development of ´53Cr analysis. The Tamengo Formation is the target of this work due to its well defined deposition interval (between 555 and 541My), ideal to the proposed investigation. This unit is also target of the ICDP's GRIND project (International Continental Scientific Drilling Project - Geological Research through Integrated Neoproterozoic Drilling), to which this work is attached, which will allow the acquisition of unaltered samples to the isotopic analysis. Moreover, this project aims to deep the studies of the Tamengo Formation, with new ´53Cr data and survey of new columnar sections in the Serra da Bodoquena region, since most of the recent studies focused on sections in Corumbá. This will allow the comparison between both localities and their paleoenvironmental settings, of deep and shallow waters, respectively. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FERNANDES, HENRIQUE ALBUQUERQUE; BOGGIANI, PAULO CESAR; VIANA, AGHATA ZARELLI; CAETANO-FILHO, SERGIO; PEREIRA, LUIZ GUSTAVO; FREITAS, BERNARDO TAVARES; HIPPERT, JOAO PEDRO; MORAIS, LUANA; TRINDADE, RICARDO IVAN FERREIRA. New advances on the carbon isotope and rare earth elements chemostratigraphy of the late Ediacaran Tamengo Formation (Corumba Group, Brazil). Journal of South American Earth Sciences, v. 133, p. 19-pg., 2023-11-27. (16/06114-6, 20/16140-0, 21/02628-3)

FERNANDES, HENRIQUE ALBUQUERQUE; BOGGIANIA, PAULO CESAR; FREDERIKSEN, JESPER ALLAN; CAMPOS, MARCELO DA ROZ; CARDOSO-LUCAS, VINICIUS; FREITAS, BERNARDO TAVARES; FREI, ROBERT. Rapid bioproductivity recovery following the Marinoan glaciation: Evidence from Sr-Cr-Cd isotopes and trace elements in the Morraria do Sul cap dolostone, Brazil. CHEMICAL GEOLOGY, v. 673, p. 21-pg., 2024-12-07. (21/02628-3, 20/16140-0, 23/02223-9)