This project proposes the geochemical investigation related to rock magnetic and paleomagnetic data on selected ferromanganese (Fe-Mn) crusts collected from three distinct regions of the Atlantic Ocean, i.e, the Eastern Rio Grande Rise (ERGR), the Western Rio Grande Rise (WRGR) and the Tropic seamount. Recent studies have revealed that the older layers of Fe-Mn crusts from WRGR show post-depositional diagenetic changes resulting in phosphatization under suboxic conditions during the Miocene. (Benites et al., 2020), while the crusts from Tropic seamount show a major phosphatisation event starting from 38 Ma (Josso et al., 2019). This research plans to perform a detailed geochemical study on Fe-Mn crusts from ERGR and which have not been investigated and belong to deeper water depths being less likely to be affected by phosphatization. The rock magnetic studies have shown changes in magnetic mineralogy in relation to the different diagenetically altered and phosphatized layers resulting in secondary magnetization carried by varying magnetic minerals. A continuous magnetic data combined with geochemical data along the crust sections would provide comparable and vital paleoceanographic information on a regional scale. This project is connected with the ongoing PhD FAPESP project (Bolsa no país) entitled "Magnetostratigraphic analysis of ferromanganese deposits''.
News published in Agência FAPESP Newsletter about the scholarship: