Analysis of the morphology and the sedimentary architecture of a portion of the Santos Basin continental slope to investigate a potential salt dome

• Grant number: 18/26668-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2019
• End date: December 31, 2019
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Luigi Jovane
• Grantee: Beatriz Bressan de Souza e Silva
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Between January 19th and 24th of 2018, the research group of the Oceanographic Center of Stratigraphic Records (CORE) of the Oceanographic Institute (IO) of the University of São Paulo (USP) carried out a Pre-Cruise aboard the oceanographic ship Alpha Crucis. In this Expedition, bathymetric data were collected from a multi-beam echo-sounder, seismic data were collected from a single-channel seismic profiler and sedimentary records were collected from a corer, from the Santos Basin Continental Slope region. This region comprises the area between 24° 50'-25° 02'S and 44° 24'-44° 40 'W. During the acquisition of single-channel seismic data, marine structures were observed with strata related to salt domes. These are saline bodies that underwent an ascending process, due to their lower density when compared to adjacent materials, taking the form of a dome and causing several alterations in the architecture of the sedimentary column in which they were intruded (MAHIQUES et al., 2017; SCHATTNER et al., 2018). Since the seismic profiler used in the cruise was able to reach the first hundred meters of the sedimentary column of the Continental Slope and the multibeam echo-sounder allowed a mapping of the seabed of the area, it will be possible to evaluate the recent depositional pattern overlying the sedimentary package directly influenced by these structures. Thus, the association between the bathymetric and seismic data acquired aboard Alpha Crucis will be crucial for the description of the pattern of the bottom morphology and the sedimentary architecture of the first hundred meters of the sedimentary column of the Continental Slope off Santos. Therefore, it will be possible to evaluate if these patterns are modified in the regions overlying the salt domes in comparison to those more distal from these structures. In addition, the results of the seismic analysis can be tied to the information acquired from sedimentary records collected in the region, also during the shipment of January 2018, which will be analyzed by IO Postgraduate students, in order to corroborate with the information acquired through the geophysical analysis.