Objectives of the cruise:
The objective of this study was to characterize the spatial and temporal variations of Quaternary deposits off the Sao Marcos Bay and the Bay of Arraial (offshore Sao Luis, Maranhão State, North Brazil). In other words, the objective is to define a 4-dimensional model of sedimentary architecture from the continental shelf to the top of the slope. The general architecture of the margin was studied and imaged during the Brazilian academic campaigns LEPLAC (phase 1 and phase 2, e.g. Reis et al., 2016). The continental slope has also been recently studied during the MAGIC Campaign (2012) (Ifremer Coll. / IUEM / Petrobras / Univ Brasilia). The study of more specific geochemical transfers (C, Hg and trace metals) was carried out recently by the Brazilian teams (eg Gomes et al., 2009, Costa & Lacerda 2009, Sabadini-Santos et al., 2013, Lacerda et al., 2014). During the SHEOPS campaign, we intended to 1) complement the image of the zone with multibeam bathymetric shallow data, sediment profiler, and high resolution seismic on the continental shelf, 2) track current characterization and potential nepheloid layers (using ADCP and CTD measurements) in order to obtain a complete understanding of platform-slope connection. The campaign also initially intended to provide 3) a measure of in situ and continuous flows of water-to-air CO2 and to make some samples from a Box-Corer. Unfortunetly we could not do this last third objective because our collegues from Univ. Ceara could not embark neither their equipments nor their scientific personnel.

Collaborative Context:
This project is part of a long-term Franco-Brazilian collaboration with several Brazilian laboratories, in particular the Geomargem Group (UERJ-UFF-UPMC-IUEM), which has already given rise to numerous international joint publications (e.g. Reis et al., 2016; Rabineau et al., 2015; Rabineau et al., 2014; Reis et al. 2013; Marangoni et al., 2013; Gorini et al., 2013; Maia et al., 2010; Reis et al., 2010; Fleming et al., 2009; Reis et al., 2008; Droz et al., 2006; Weibull et al., 2006; Reis et al., 2005; Gorini et el., 2005), and the group (Ifremer / IUEM / Petrobras / Univ Brasilia), which has already carried out three offshore campaigns on the Brazilian margins (SANBA, 2010, MAGIC, 2012 and SALSA, 2014) (Aslanian, Moulin et al., 2013, 2015 and 2016, Evain et al., 2015, Mokeddem et al., in press).