INACMA - Inorganic Nanoparticles in Archaean Carbonaceous Matter - a key to early life and palaeoenvironmental reconstructions

Earth is a dynamic system influenced by the interactions between life and physical environments at all scales of space and time. Though our planet is ~4.6 Gyr old, we don’t know yet when and in which environmental conditions it first became home to life. The early rocks hold the answers to these questions, but in a scattered and fragmentary manner with traces of life often being highly altered. This project could provide a substantial contribution to the understanding of early life on Earth: Inorganic Nanoparticles (IN) in Archaean (A) Carbonaceous Matter (CMa) will be investigated to decipher crucial aspects of early life framed in its environmental context. IN are naturally formed and removed from the environment by various chemical and biological processes. Relationships between microorganisms and adsorption of specific IN, and physico-chemical parameters have been observed in natural environments. Therefore, IN have a great potential as a biosignature and paleoenvironmental proxy when associated to fossil objects. Archaean cherts of Barberton greenstone belt (South Africa) contain the oldest known traces of fossil life in a well-preserved geological context. Micro-/nano-scale investigations of the nature and distribution of CMa and related IN in these primitive cherts by using a combination of high resolution microscopy techniques, will allow to: • evaluate the composition and texture of carbonaceous chert, and identify the nature of the CMa and its IN; • establish a relationship between IN content and specific types of CMa; • explore their roles in the Archaean bio-geochemical processes, and their potential as biosignatures. This project combines the experience of the applicant in biosignatures, her expertise in microscopy, and a network of internationally reputed scientists. The CIG Grant can make possible to realize this project, support the researchers integration at the Host Institutions, and enhance her academic carrier to obtain a professorship position