Episodic sea-floor spreading in the Southern Red Sea

Almalki, Khalid A.; Betts, Peter Graham; Aillères, Laurent

doi:10.1016/j.tecto.2014.01.030

Cited by 41 publications

(26 citation statements)

References 54 publications

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“…A classic example is the reconstruction of the Atlantic, where the easternmost convex part of the South American Plate can be joined with the western concave part of the African Plate. The Red Sea is another example; it experienced a transition from continental rifting to active mid‐ocean ridge spreading about 5 Ma (Bosworth et al ., , Almalki et al ., ). The continental‐oceanic boundary is sinuous with a conjugate pattern of concave to convex sections of the margins, having an overall orientation that is consistent with the NE‐SW spreading direction (Fig.…”

Section: Discussion: the Conjugate Pattern Of The Continental Marginmentioning

confidence: 97%

Conjugate margin pattern of the Southwest Sub‐basin, South China Sea: insights from deformation structures in the continent‐ocean transition zone

Ding

2015

Geological Journal

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Eight cross-sections from the continent-ocean transition zone of the Southwest Sub-basin, South China Sea, have been used to compare conjugate rifted margins that are typical of magma-poor rift systems. The geological timing of the break-up unconformity in the continental margins shows that the Reed Bank and the Dangerous Grounds in the south continental margin connect with the Zhongsha Islands and the western Phu Khanh Basin, which experienced northwest-southeast oriented movement after the opening of the Southwest Sub-basin. Detailed interpretations identify a range of deformational and sedimentary features in the continent-ocean transition zones with and without rigid blocks. Remarkable structural similarities appear in the transition zone lying within the convex-shaped area shaped by rigid blocks of the conjugate margin (e.g. the Zhongsha Islands and the Reed Bank) or within concave-shaped areas sandwiched by rigid blocks. Rigid tectonic blocks such as the Zhongsha Islands and the Reed Bank played important roles in both the shaping of the continent-ocean boundary and the initial continental break-up.

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Section: Discussion: the Conjugate Pattern Of The Continental Marginmentioning

confidence: 97%

Conjugate margin pattern of the Southwest Sub‐basin, South China Sea: insights from deformation structures in the continent‐ocean transition zone

Ding

2015

Geological Journal

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“…In addition to the clear anomalies in the centre of the basin, Girdler and Styles (1974) and Hall (1989) also interpreted the low magnetic anomalies over the southern Red Sea shelves as seafloor spreading magnetic stripes, suggesting the Red Sea was formed by two stages of seafloor spreading. Based on magnetic and gravity modelling constrained by the seismic refraction data of Gettings et al (1986) and Mooney et al (1985), Almalki et al (2014) recently suggested that about 75 km of oceanic crust formed before Middle to Late Miocene (15-5 Ma) under the Farasan Bank (Figure 1), which supports a two-stage spreading evolution of the Red Sea. In contrast, Cochran (1983) argued that these magnetic anomalies result from a wide region of mafic diking and intrusions rather than a continuous oceanic crust of dykes and extrusives, because the anomalies have low amplitudes (less than 200 nT) and long wavelengths (20-50 km).…”

Section: Continental Rifting and Seafloor Spreading In The Northern Amentioning

confidence: 95%

Oceanic-like axial crustal high in the central Red Sea

et al. 2018

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“…Almalki et al . () described normal faults in the Farasan Islands, which are oriented sub‐parallel with the adjacent spreading centre. They imply that some extension occurred after the Miocene on the flanks of the ridge.…”

Section: Discussionmentioning

confidence: 99%

Deformation of a young salt giant: regional topography of the Red Sea Miocene evaporites

et al. 2015

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The deformational behaviour of 'salt giants' during and shortly after their deposition is difficult to decipher in ocean margin settings where the original evaporites have been deeply buried and strongly mobilized. Here, we examine seismic reflection data from the Red Sea, where evaporites deposited until the end of the Miocene (~5.3 Ma), are generally covered by only 200-300 m of low-density sediments and where the presence of an axial spreading centre allows us to observe how they have responded to a varied configuration of underlying basement. The regional morphology of the Sreflection, representing the evaporite surface, is mapped out from seismic data from 13 cruises. The S-reflection is locally rugged and commonly angular. It is either underlain by layered reflectivity, suggestive of layered evaporite beds, or by more transparent seismic character, suggestive of massive halite. On average, the depth of the reflection on the flanks of the axial rift systematically declines from 700 to 1100 m below sea level (mbsl) going northwards from 16 to 23°N. In the central Red Sea, the S-reflection has 100-to 200-m-deep depressions, extending towards the coasts in places. In the southern Red Sea, the S-reflection forms a surface at 300-800 mbsl that appears less disrupted. We suggest that the evaporites originally had a flat, horizontal surface at the end of the Miocene and have subsequently been distorted by isostatic effects and axial rifting, which in turn promoted evaporite flowage. Off-axis evaporite depressions correspond with flows identified with multibeam sonar. Furthermore, across-rift lows in Bouguer gravity anomalies represent valleys in the underlying basement. The off-axis evaporite depressions overlie those valleys, as would be expected if halokinetic movements were greatest where the evaporites are locally thick, leading to deflation of the evaporite surface. The thickness of post-Miocene sediment, also mapped out as part of this procedure, confirms the generally pelagic nature of this interval and increases on average from~250 to 300 m from the central to the southern Red Sea, mimicking the variation in pelagic productivity observed in the present water column.

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Episodic sea-floor spreading in the Southern Red Sea

Cited by 41 publications

References 54 publications

Conjugate margin pattern of the Southwest Sub‐basin, South China Sea: insights from deformation structures in the continent‐ocean transition zone

Conjugate margin pattern of the Southwest Sub‐basin, South China Sea: insights from deformation structures in the continent‐ocean transition zone

Oceanic-like axial crustal high in the central Red Sea

Deformation of a young salt giant: regional topography of the Red Sea Miocene evaporites

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