Exploration plays of the Potiguar Basin in deep and ultra-deep water, Brazilian Equatorial Margin

Author(s):  
Ediane B. da Silva ◽  
Helio J.P. Severiano Ribeiro ◽  
Eliane Soares de Souza
Keyword(s):  
2020 ◽  
Author(s):  
Yoe Perez ◽  
Julia Fonseca ◽  
Helenice Vital ◽  
Andre Silva ◽  
David Castro

<p>The Brazilian Continental Margin (BEM) deep-water regions contain important geological features that need advance in their characterization. Mass-transport deposits (MTD) are important not only by their significance in the sedimentary but also because of their negative impact economically. A slump is a coherent mass of sediment that moves on a concave-up glide plane and undergoes rotational movements causing internal deformation and one of the basic types of MTD. The study area comprises part of the offshore Potiguar Basin in NE Brazil, on the distal eastern portion of the Touros High and Fernando de Noronha Ridge. This portion of the Potiguar Basin comprises a transform rift system that has evolved into a continental passive margin. This basin represents an important location related to the breakup between South America and Africa. The database used in this work included 2D post-stack time-migrated seismic profiles from the Brazilian Agency of Petroleum, Natural Gas, and Biofuels (ANP). The slumps reflectors are identified on the continental shelf profiles in form of present clinoform configuration, medium to high continuity, high amplitudes, and medium to high frequencies, representing a sigmoidal oblique complex prograding reflector. The slump scars at the continental slope indicate that this is a gravitationally unstable area that will eventually collapse, resulting in erosional features on the continental slope and deposition on the continental rise. Our results provide some insights regarding MDT slumps sedimentary evolution in the BEM deep water area as well as their interrelation with other sedimentary deposits.</p>


2019 ◽  
Vol 36 ◽  
pp. 1-13
Author(s):  
José De Assis ◽  
Jose Souza ◽  
Manuela Lima ◽  
Gislaine Lima ◽  
Ralf Cordeiro ◽  
...  

Polynoid scale-worms have been found living as commensals with deep-water antipatharians (commonly known as black corals) in the Potiguar Basin, off Rio Grande do Norte State, Northeastern Brazil. In this paper two polychaete species and four black corals species are redescribed. Benhamipolynoecf.antipathicola and Parahololepidellacf.greeffi, and the black coral Stylopathesadinocrada Opresko, 2006 are recorded for the Southwestern Atlantic. Benhamipolynoecf.antipathicola was first described from off New Zealand and the Malay Archipelago, as symbiont with the black coral Stylopathestenuispina (Silberfeld, 1909). It was later reported for the North Atlantic, off Florida, associated with Stylopathescolumnaris (Duchassaing, 1870). In our study, B.cf.antipathicola was found in association with the black coral S.adinocrada. Parahololepidellacf.greeffi was first described as a free-living from shallow waters off São Tomé and Cabo Verde Islands, West Africa, and later reported as symbiont with the black coral Tanacetipathescf.spinescens in the same location. Our data expand both the geographical distribution and the host range of this species which is reported for the first time as symbiont with Tanacetipathesbarbadensis (Brook, 1889), T.tanacetum (Pourtalès, 1880) and T.thamnea (Warner, 1981) in Brazil. The aim of this study is to discuss commensal associations between two species of scale-worm polynoids and black corals found in the Southwestern Atlantic, and also reporting their global distribution. Finally, we provided an updated list of the commensal polynoids and their black coral hosts.


2019 ◽  
Vol 40 (6) ◽  
pp. 977-988 ◽  
Author(s):  
Júlia C. L. G. Fonseca ◽  
Helenice Vital ◽  
Yoe A. R. Perez ◽  
David L. Castro ◽  
André G. Aquino da Silva ◽  
...  

Author(s):  
João Augusto de Oliveira Cunha ◽  
Valéria Centurion Córdoba ◽  
Ubiraci Manoel Soares ◽  
Debora do Carmo Sousa ◽  
Helenice Vital

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.


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