Investigation of Rare Earth Elements from carbonate rocks of the Nama Group (Namibia): interpretation of the geochemical conditions of the Ediacaran sea

• Grant number: 23/07519-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2023
• End date: October 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Paulo César Boggiani
• Grantee: Camila Sayuri Kinoshita
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Nama Group (Namibia) is one of the most complete and well-preserved sedimentary records of the Ediacaran-Cambrian transition. From this record, it is possible to explore the environmental and biological changes that defined this period of Earth's history. The GRIND (Geological Research through Integrated Neoproterozoic Drilling) project of the ICDP (International Continental Scientific Drilling) made it possible to collect samples from drilling cores in layers of the Nama Group, including the Ediacaran-Cambrian boundary. The present project aims to analyze the concentrations of REEs (rare-earth elements) and yttrium of limestones and dolomites from these samples to carry out paleoenvironmental interpretations, reconstructing the seawater chemistry and verifying the redox conditions and the influence of hydrothermal fluids in the samples. For this purpose, samples will be prepared by specific digestion and leaching procedures for carbonate rocks in order to remove detrital contaminants and then analyzed in an inductively coupled plasma mass spectrometry (ICP-MS). It is expected that the results obtained contribute to the understanding of environmental changes before, during and after the transition from the Ediacaran to the Cambrian.