Faulting of salt-withdrawal basins during early halokinesis: Effects on the Paleogene Rio Doce Canyon system (Espírito Santo Basin, Brazil)

Abstract

A B S T R A C TThree-dimensional seismic-reflection data are used in the analysis of submarine channel systems in the Espírito Santo Basin, Brazil. The exceptional quality of the studied data set allows the detailed documentation of the geometry, regional distribution, and statistical parameters of salt-related normal faults, and their effect on the Rio Doce Canyon system (RDCS). On the Espírito Santo continental slope, normal faulting was triggered during early halokinesis (stage A) but barely controlled the initial evolution of the RDCS, which incised the continental slope axially within a salt-withdrawal basin. However, in a second stage (stage B), crestal or radial faults controlled erosion over growing salt structures, whereas synclinal and channelmargin fault sets dissected overbank strata to the RDCS. In the later part of stage B, channel sinuosity decreased sharply in response to fault activity and associated sea-floor destabilization. Vertical propagation of blind faults was triggered in a third stage (stage C), in association with crestal collapse of buried salt anticlines and regional diapirism, but synclinal and channel-margin faults did not propagate vertically above a regional unconformity marking the base of stage C strata. Statistical analyses of observed fault sets demonstrate that synclinal faults are in average 2.3 times longer than the crestal or radial types but record 60% of the throw (average 83 m [272 ft]) experienced by the latter. In addition, the Tiago is a research lecturer at Cardiff University. After completing his Ph.D. in geology at the University of Manchester, he worked in Portugal and then Greece through the umbrella of European Union projects (EURODOM and HERMES) dedicated to the study of continental margins. His research interests include the study of deep-water rift basins and overlying postrift successions. He is particularly interested in investigating the way tectonics influences sedimentation using novel statistical methods, petrophysical, and 3-D seismic data.Joe received his B.A. and D.Phil degrees in geology from Oxford University. He is a research professor of geophysics and the director of the 3-D Lab at Cardiff University. His research interests focus on 3-D seismic interpretation in basin analysis, with special emphasis on seal integrity analysis, the genesis of polygonal faults, the emplacement of sandstone and igneous intrusions, and silica diagenesis.Richard is a professor of petroleum geoscience and the director for the Center for Research into Earth Energy Systems at Durham University. He was formerly at ExxonMobil for 8 years. He has published more than 40 articles on the use of 3-D seismic data for understanding sedimentary, fluid flow, structural, igneous, and diagenetic processes in basins.fault sets are shown to have contributed to local cannibalization of the sea floor, vertical stacking of channel-fill strata, and structural and depositional compartmentalization of potential reservoir successions. As a result, channel systems show marked differences in ...

The Role of Mass Wasting In the Progressive Development Of Submarine Channels (Espírito Santo Basin, Se Brazil)

“…An early-drift transgressive megasequence records a phase of gradual deepening of the Espírito Santo Basin from Albian to the end of the Cretaceous. In detail, it is composed of Albian shallow-water carbonate and overlying Upper Albian to Paleocene muddy and sandy turbidites (Davison 1999;Fiduk et al 2004;Alves et al 2009). A latedrift regressive megasequence was deposited from the Eocene to the present day.…”

Quantitative seismic geomorphology of a submarine channel system in SE Brazil (Espírito Santo Basin): Scale comparison with other submarine channel systems

“…3). The transgressive megasequence consists of Albian carbonate platforms accumulated below muddy and sandy turbidites, and marks a general deepening-upwards trend towards the end of the Cretaceous (Davison, 1999;Fiduk et al, 2004;Alves et al, 2009). The regressive megasequence marks the reactivation of rift structures and episodic magmatic activity (Demercian et al, 1993;Cobbold et al, 2001;Mohriak et al, 2008), and is associated with the emplacement of the Abrolhos Bank to the north of the study area (Cordani, 1970).…”

“…Various architectural elements, such as mass-transport deposits (MTDs), turbidite lobes, submarine canyons and channels are observed within a salt-withdrawal basin delimited by salt diapirs D1 to D6 (Gamboa and Alves, 2015). These elements are strongly influenced by the relative location and movement of the salt diapirs (Baudon and Cartwright, 2008;Alves et al, 2009;Gamboa et al, 2012;Gamboa and Alves, 2015). Topographic confinement created by salt diapirs is reflected by changes in channel density, geometry and sinuosity (Alves et al, 2009;Gamboa et al, 2012).…”

“…These elements are strongly influenced by the relative location and movement of the salt diapirs (Baudon and Cartwright, 2008;Alves et al, 2009;Gamboa et al, 2012;Gamboa and Alves, 2015). Topographic confinement created by salt diapirs is reflected by changes in channel density, geometry and sinuosity (Alves et al, 2009;Gamboa et al, 2012). As an example, channel density decreases from the unconfined region to the topographically confined region (Gamboa et al, 2012).…”

“…At least three major channel events have been identified within the Rio Doce Canyon system (Fig. 5): (1) an Eocene channel system controlled by adjacent faults generated on the flanks of growing diapirs (Alves et al, 2009), (2) a Miocene channel system with multiple laterally shifting channels, and (3) a PlioceneQuaternary channel complex set confined by salt diapirs (Gamboa et al, 2012) (Fig. 5).…”