Cr-Cd-Sr isotopes and trace elements in Ediacaran carbonates of the Corumbá and Nama groups (Brazil and Namibia): tracking atmospheric oxygenation and paleoproductivity

• Grant number: 23/02223-9
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: August 10, 2023
• End date: February 09, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Paulo César Boggiani
• Grantee: Henrique Albuquerque Fernandes
• Supervisor: Robert Frei
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Copenhagen, Denmark
• Associated to the scholarship: 21/02628-3 - Investigation of oxygen levels in the Ediacaran through isotopic chemostratigraphy (C, Sr, Cr, Cd) of the Tamengo Formation-Corumbá Group, BP.DD

Abstract

The Late Ediacaran is a period of major perturbations in the Earth System that ultimately paved the way to a Phanerozoic World. Among these upheavals, there is the rise of oxygen levels in the atmosphere-ocean system, which may be linked to the emergence of complex life on Earth. In order to investigate these oxygen fluctuations, geochemical proxies based on stable isotopes have been successfully applied in ancient rocks. The aim of this project is to perform Cr, Cd and Sr isotope analyses and trace elements geochemistry in carbonate rocks from the Nama and Corumbá groups, both excellent archives of the Late Ediacaran in Namibia and Brazil, respectively. The samples selected for this project are from drill cores from the ICDP's GRIND (Geological Research through Integrated Neoproterozoic Drilling) project. This project is a collaboration of multiple research groups worldwide along with ICDP (International Continental Scientific Drilling Program) that aims to understand the biological diversification and the environmental changes during the Ediacaran through paleontological, geochemical, paleomagnetic and sedimentological research in a series of drill cores in Ediacaran strata. This gives the opportunity to work with core samples, free from surface alteration. Samples from the Nama Group and Tamengo Formation will be analyzed in a thermal ionization mass spectrometer (TIMS) at the University of Copenhagen, under guidance of Dr. Robert Frei and with cooperation of the PhD student Samantha Walker and the post-doc Jesper Frederiksen. The proposed work will be carried out from August 2023 to February 2024 and is crucial to the completion of the current PhD thesis. (AU)