Paleomagnetic analysis of the Cerro Negro Formation, La Providencia Group (Ediacarano, Argentina)

• Grant number: 16/25450-7
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): May 01, 2017
• Effective date (End): December 31, 2018
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal researcher: Giancarlo Scardia
• Grantee: Manoela Machado Papel
• Home Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

A recent model suggests a connection between geomagnetism and the biological innovation known as Cambrian Explosion, occurred at ca 542 million years (Ma). The hypothesis relies on the analysis of the environmental pressure which may have been produced in the Ediacaran fauna by an extraordinarily high rate of polarity inversions of the Earth's magnetic field, in order of 20-24 per Ma. However, the model is exclusively based on Northern Hemisphere data, which have been collected in tectonically deformed terrains (Baltic and Siberia), where the preservation of the original rock's magnetization can be questioned. The project "Multi-proxy analysis of the Cerro Negro Formation, Argentina: biostratigraphy and paleoenvironment of the first South America Ediacaran fossil lagerstätte", coordinated by Prof. Dr. Lucas Warren and founded by FAPESP (proc. 2015/24608-3), offers a unique opportunity to test this hypothesis by combining new paleomagnetic data with the paleontological data collected in the framework of the project in the Rio de la Plata Craton, where the tectonic deformation is very low and the original magnetization preservation potential is quite high. The data obtained by this IC will be also used to compare the Cerro Negro Fm magnetostratigraphy with other polarity scales available from literature for the considered time interval and can provide new information about the apparent migration path of the Gondwana paleomagnetic pole and the depositional paleolatitude. (AU)