Connecting onshore-offshore Campos Basin structures: Interpretation of high-resolution airborne magnetic data

Abstract

We interpreted northwest-trending transfer faults whose extensions are not entirely mapped in the Precambrian basement of the onshore and offshore Campos Basin. To enhance the subtle northwest–southeast lineaments not clearly seen in the total-field data, we reprocessed and merged two airborne magnetic data sets aiming at producing a single merged magnetic data set. Next, we applied a directional filter to these integrated magnetic data. Finally, we applied a multiscale edge detection method to these filtered data. This combination allowed the detection of edges and ridges that are used to produce several northwest–southeast lineations. We interpreted these northwest-trending lineations as magnetic expressions of transfer faults that cut across the onshore adjacent basement of the Campos Basin to the shallow and deep Campos Basin waters. These interpreted northwest-trending faults suggested the continuity of the known northwest-striking transfer faults in the deep Campos Basin waters toward the shallow Campos Basin waters and the adjacent continent. Moreover, our interpreted northwest-trending faults revealed the control of several known oilfields in the Campos Basin. This result supported the hypothesis of the influence of the northwest–southeast-trending transfer faults on the petroleum system of Campos Basin, which were reactivated in the Tertiary providing a pathway for the turbidite sedimentation, reworking, and redistribution of several deepwater reservoirs. In addition, it was hypothesized that this faulting system controlled the hydrocarbon migration paths from the presalt source rocks through salt windows into basal suprasalt layers.

The Alegre Lineament and its role over the tectonic evolution of the Campos Basin and adjacent continental margin, Southeastern Brazil

“…The NW-SE faults mapped in our work (Fig. 14) are considered transfer faults, in agreement with Cobbold et al (2001), Meisling et al (2001), Stanton et al (2010) and Lourenço et al (2014). A set of NW-SE transfer faults affects the Campos Fault and dislocates the NE-SW trace in various stepped segments (Oliveira, 2015).…”

“…Fig. 10b illustrates a negative flower structure associated with basement faults, which occur in the same position as the transfer faults described in the literature (Cobbold et al, 2001;Meisling et al, 2001;Lourenço et al, 2014).…”

“…10a shows faults that delimit a structural high corresponding to the Badejo High, identified earlier by Guardado et al (2000). Aeromagnetic data reported by Stanton et al (2010) and Lourenço et al (2014) show the alignment of a NNW-SSE trending negative magnetic anomaly separating the Badejo High from the Campos Magnetic High. Fig.…”

“…14c). Thus, those NW-SE faults were considered transfer faults (dashed black lines), which can be associated with the transfer faults described by Cobbold et al (2001), Meisling et al (2001), Stanton et al (2010) and Lourenço et al (2014). Oliveira (2015) also identified NW-SE transfer faults (blue dashed lines) near the shoreline, which separate various segments of the Campos Fault compounding an echelon pattern.…”

Significado e influência do lineamento alegre na evolução tectônica da bacia de campos e margem continental adjacente, sudeste do Brasil

“…Buscaram-se indicativos de movimentação transcorrente na interpretação das seções sísmicas, mas, dentre as 31 seções disponíveis, apenas 3 apresentaram indícios de movimentação transcorrente. Na figura 2.8b é possível observar uma estrutura em flor negativa associada a falhas no Embasamento, que ocorre na mesma posição das falhas de transferência citadas na literatura (Cobbold et al, 2001;Meisling et al, 2001;Lourenço et al, 2014). No Embasamento e na Sequência Rifte, tanto as falhas sintéticas quanto as antitéticas possuem rejeito normal aparente, com médio a alto ângulo de mergulho.…”