Fossil diagenesis of ichnofossils associated by microbial mats

• Grant number: 22/04484-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2022
• End date: February 29, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Fresia Soledad Ricardi Torres Branco
• Grantee: Bruno Belila Rusinelli
• Host Institution: Instituto de Geociências (IG). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The development of biofilms and microbial mats during deposition of sediments occur in a variety of environments from marine to continentals. Microbial action in sediments promote mechanical stabilization and mineral precipitation that can help cementation in early eodiagenesis. During this process, interactions between sediments and organisms with biofilms and/or microbial mats presence can promote synchronous preservation in biogenic structure, like ichnofossils. This process appears to have a wide environmental and temporal occurrence in geologic record, and is interesting to comprehend such a process for taphonomy study of ichnofossils, as well as contribute to understanding biogenicity in sedimentary structures. In this research, the ichnofossils studied are from Ipu (Silurian-Parnaíba Basin), Botucatu (Late Jurassic to Early Cretaceous - Paraná Basin) and Sousa formations (Cretaceous - Sousa Basin), that represent environments from coastal - like Ipu Formation - to continentals, like eolian deposits in Botucatu Formation and lacustrine in Sousa Formation. With the purpose of attesting biofilms and/or microbial mats influence (biosignature) in preservation of several ichnotaxa from different environments and lithology, samples will be collected, with description of collection areas, petrographic analysis, Scanning Electron Microscopy and Energy Dispersive x-ray Spectroscopy analyses (SEM/EDS) in thin sections and samples, and for a detailing of the composition and mineral it will be used Synchrotron Light Technique. The intended purpose is to compare this study objects with those from other Gondwana localities and modern analogues of microbial mats, observing the main structures and features that can prove the biogenicity in the samples analyzed. With a multi-technical analysis, it will be possible to associate petrographic structures and texture with analytic data, as well as contribute to future study in taphonomy of ichnofossil or even about products and processes related with microbial action in sediments. (AU)