Quaternary Shelf Sedimentary Systems Off Rio De Janeiro State, Ne Santos Basin – Brazil

The combined analysis of sparker monochannel seismic<br>reflection data acquired by GEOMAR missions in the<br>early 80’s and data from exploratory wells provides new<br>insights into the shallow sedimentary record (~400 ms<br>penetration) of the continental shelf systems along Rio de<br>Janeiro state. The seismic data display a pattern of<br>stacked prograding shelf wedges composing 8 major<br>seismic sequences (SqC to SqA and Sq1 to Sq5), limited<br>by unconformity surfaces (S0-S5) that suggest erosive<br>processes indicative of prolonged subaerial exposure of<br>the continental shelf. Sequences can be grouped into two<br>distinct sets according to the geometry of their clinoforms,<br>which are either dominantly sigmoidal (Set II) or<br>dominantly oblique (Set II). Indirect correlation with<br>seismic data from Silva (1992) points to an age of circa<br>0,5 My(Middle-Upper Pleistocene) for the erosive surface<br>S1, whereas correlation with well data (by well projection)<br>hints that S0 might be placed within the Pliocene<br>stratigraphic window. Finally, interpretation of seismic and<br>well data supports the hypothesis that the depositional<br>pattern of sequences Sq1-Sq5 records a 100 kyr<br>glacioeustatic cycle.