Diapir exposure at the ocean floor as a new paleo-currents indicator: a case study from Santos Basin, offshore Brazil

• Grant number: 19/06250-5
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2019
• End date: August 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
• Principal Investigator: Michel Michaelovitch de Mahiques
• Grantee: Michel Michaelovitch de Mahiques
• Principal researcher abroad: Uri Schattner
• Institution abroad: University of Haifa, Israel
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/00256-1 - Geochronology and terrigenous sedimentation of the mud depocenters from the Southern Brazilian continental shelf, AP.R

Abstract

Ocean bottom currents play a central role in the marine system. They transport water masses across the globe while distributing sediments, isotopes and nutrients, as well as reshaping the ocean floor along their path. While the mapping of present-day ocean bottom currents relays on direct measurements, reconstruction of paleo-currents is based on specific stratigraphic indicators, such as cross-bedding and ripple marks. On a regional scale, the paleo-current indicators assist in reconstructing ocean bottom conditions that alter through geological times. In theory, these conditions are dictated by the local settings and regional circulation patterns. Both are difficult to reconstruct due to the poor coverage of three-dimensional data across the subsurface of the world oceans. In our recent joint paper (Schattner et al., 2018) we defined the interaction between exposed salt diapirs at the seafloor and the morpho-stratigraphic response due to the flow of bottom currents. This definition coins a new paleo-current indicator that allows identifying both the timing of exposure and the action of bottom currents and hence the paleo-conditions and their timing. In the research proposed here, we wish to utilize the diapir exposure concept to map paleo-currents across the diapir-rich Santos basin, offshore southeast Brazil. We relay the research on an extensive interpretation of multichannel seismic reflection data initially acquired for industrial purposes. The planned research mainly requires lab work for data analysis, which is done jointly, and therefore traveling costs are crucial for the project success. This project will continue a fruitful collaboration between de Mahiques and Schattner, that since 2014 yielded five published peer review papers, additional two accepted for publication recently, and three manuscripts in preparation, attendance in international meetings, two joint cruises in the southwest Atlantic, and several mutual visits. We expect that once published this study will have an essential contribution to the field of exploration geophysics, since it provides a unique perspective on the formation and availability of reservoir source rocks. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE MAHIQUES, M. M.; LOBO, F. J.; SCHATTNER, U.; LOPEZ-QUIROS, A.; ROCHA, C. B.; DIAS, R. J. S.; MONTOYA-MONTES, I; VIEIRA, A. C. B.. Geomorphological imprint of opposing ocean bottom currents, a case study from the southeastern Brazilian Atlantic margin. MARINE GEOLOGY, v. 444, FEB 2022. (14/08266-2, 10/06147-5, 19/06250-5, 15/17763-2, 20/03363-0)

SCHATTNER, URI; DE MAHIQUES, MICHEL MICHAELOVITCH. Post-rift regional volcanism in southern Santos Basin and the uplift of the adjacent South American coastal range. Journal of South American Earth Sciences, v. 104, DEC 2020. (15/17763-2, 19/06250-5)