A phase of transient subsidence, sediment bypass and deposition of regressive–transgressive cycles during the breakup of Iberia and Newfoundland

Spatial and Temporal Evolution of Rifting and Continental Breakup in the Eastern Black Sea Basin Revealed by Long‐Offset Seismic Reflection Data

“…The S3‐S4‐S5a units show an along‐strike change in stratigraphic character that appears to be intermediate between synrift and postrift sequences. The seismic character of these units shows similarities with the definition of breakup sequences given by Soares et al () and Alves and Cunha (). Similar to this definition, S3 to S5a units record the transitional period between the onset of breakup (SE) and the end of extension (NW), followed by the establishment of thermal relaxation as the main process controlling subsidence in the basin.…”

“…Similar to this definition, S3 to S5a units record the transitional period between the onset of breakup (SE) and the end of extension (NW), followed by the establishment of thermal relaxation as the main process controlling subsidence in the basin. Based on seismic evidence along the west Iberia‐Newfoundland margins, Alves and Cunha () identified within the breakup sequence distinct seismic intervals of chaotic to partly continuous seismic reflections terminating against the slope fault system and interpreted these intervals as mass‐wasting and turbiditic deposits associated to the breakup stage. These units are then gradually draped by wavy to subparallel, low‐amplitude seismic reflections interpreted to reflect the spreading conditions on a fully developed margin.…”

“…Due to the complex definition of rift and breakup processes, previous studies introduced the idea of a transition sequence recording the gradual transition from synrift to postrift stage (e.g., Moore, 1992). This idea has been further developed by more recent studies, acknowledging breakup as a prolonged event identified by a discernible unconformity-bounded stratigraphic sequence of regional extent, showing distinct depositional architectures compared to older (synrift) strata and younger (postrift) units: the breakup sequence (e.g., Alves & Cunha, 2018;Soares et al, 2012). Here we refer to a recent definition of breakup sequence by Soares et al (2012), which describes the character of some sedimentary units deposited from the onset of lithospheric breakup to the establishment of thermal relaxation as the main process controlling the subsidence of the basin.…”

Depositional architecture and structural evolution of a region immediately inboard of the locus of continental breakup (Liwan Sub-basin, South China Sea)

“…2). Thus, we define the sequence boundary dated as ~33 Ma to be a breakup unconformity (T70 in Figure 2), bounding a breakup sequence at its base (Alves and Cunha, 2018;Soares et al, 2012;Zhao et al, 2016). The stratigraphic units and associated rifted structures below this breakup sequence are of primary interest to this study (Fig.…”

“…Of particular scientific interest are the architecture and tectonic evolutions of the distal domain of rifted margins, as they record the transitional period between continental rifting and the onset of seafloor spreading (Alves and Abreu Cunha, 2018;Manatschal, 2004;Soares et al, 2012).…”