The velocity structure of the sediments in the southern Rockall Basin: results from new wide-angle seismic modelling

Mackenzie, G. D.; Shannon, Patrick M.; Jacob, A. W. B.; Morewood, N. C.; Makris, J.; Gaye, M.; Egloff, F.

doi:10.1016/s0264-8172(02)00133-2

Cited by 19 publications

(34 citation statements)

References 17 publications

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“…The age, distribution and thickness of the prePalaeogene stratigraphic intervals are mainly inferred from velocity data derived from the results of wide-angle seismic experiments (e.g. Keser Neish, 1993;Shannon et al, 1994;O'Reilly et al, 1995;Shannon et al, 1999;Mackenzie et al, 2002;Morewood et al, 2005).…”

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

“…Naylor and Shannon, 2005;Mackenzie et al, 2002). There are also a number of narrow, NNE-to NE-trending, mainly Mesozoic to Late Palaeozoic remnant half-grabens developed on both flanks of the Rockall Basin (see Naylor et al, 1999), the most important of which are the contiguous NNE-trending Slyne and NE-trending Erris basins on the eastern margin of the basin.…”

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

“…The crystalline crust is approximately 6 km thick, with the Moho interpreted to lie at a depth of 14 km and the thinnest crust occurring towards the margins of the basin (Keser Neish, 1993;Hauser et al, 1995;O'Reilly et al, 1995;Mackenzie et al, 2002, Morewood et al, 2005.…”

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

“…Jurassic-Cretaceous (Mackenzie et al, 2002); Triassic to Late Jurassic-Cretaceous ; Latest Triassic-Cretaceous (Roberts et al, 1999); Permo-Triassic to Jurassic ; Permo-Triassic, Late Jurassic and localised Early Cretaceous ; Permo-Triassic (Bott and Watts, 1971); and Carboniferous (e.g. Haszeldine and Russell, 1987).…”

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

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Three-dimensional gravity and magnetic modelling of the Irish sector of the NE Atlantic margin

2010

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A new 3D lithospheric model has been constructed using high-resolution gravity data from the Irish National Seabed Survey. The sedimentary component of the model incorporated density variations due to laterally varying overcompaction associated with Cenozoic denudation. After optimisation based on gravity inversion, regional crustal thickness variations were defined which are in reasonable agreement with the results of wide-angle seismic experiments. High crustal extension factors (β>5) characterise the deeper parts of the Rockall and Porcupine basins and in places the model indicates extreme stretching (β>10) beneath these basins. This could be because of instability in the gravity inversion, although other recent investigations have independently suggested similarly high extension factors. In contrast, the Hatton Basin is characterised by an apparent extension factor of about 2. The modelling resolves a pattern of NE-to NNE-trending local Mesozoic basins on the margins of the Rockall Trough, helping to delineate structures that were previously only sparsely sampled by seismic surveys. It appears possible that rifts with similar trends underlie the volcanic rocks which obscure the deeper parts of the Hatton Basin. The linear trends of the basins to the south and east of Ireland are interpreted to have been inherited from a basement fabric that was initially established during the late Precambrian assembly of this basement and subsequently subjected to Caledonian and Variscan reactivation. Magnetic modelling indicates that the variations in the thickness of the crystalline crust predicted by the gravity models can explain the regional magnetic anomaly patterns over the Rockall and Porcupine basins, but that significant additional magnetic material (probably igneous rocks of both Palaeogene and Cretaceous ages) is required to explain the anomalies in the Hatton Basin region. The magnetic signature of the Rockall Basin is distinctly different to that over the basement (of similar apparent thickness) formed during mid Cretaceous (C34N) opening of the ocean basin to the south. This is an impediment to hypotheses that invoke mid Cretaceous sea-floor spreading rather than intracontinental rifting to explain the development of the basin. The exception is in the extreme south of the basin where the volcanism associated with the Barra Volcanic Ridges combined with indications of relatively strong lithosphere could be evidence of incipient ocean opening.

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Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

Section: Rockall Basin and Associated Marginal Basinsmentioning

confidence: 99%

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Three-dimensional gravity and magnetic modelling of the Irish sector of the NE Atlantic margin

2010

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“…The sedimentary succession in the southern Rockall Basin (Fig. 3c) is typically 4.5 km thick and reaches a maximum of 7 km (Mackenzie et al 2002).…”

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confidence: 99%

A review of the NE Atlantic conjugate margins based on seismic refraction data

Funck

Gaina

Geissler

et al. 2016

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The NE Atlantic region evolved through several rift episodes, leading to break-up in the Eocene that was associated with voluminous magmatism along the conjugate margins of East Greenland and NW Europe. Existing seismic refraction data provide good constraints on the overall tectonic development of the margins, despite data gaps at the NE Greenland shear margin and the southern Jan Mayen microcontinent. The maximum thickness of the initial oceanic crust is 40 km at the Greenland-Iceland-Faroe Ridge, but decreases with increasing distance to the Iceland plume. High-velocity lower crust interpreted as magmatic underplating or sill intrusions is observed along most margins but disappears north of the East Greenland Ridge and the Lofoten margin, with the exception of the Vestbakken Volcanic Province at the SW Barents Sea margin. South of the narrow Lofoten margin, the European side is characterized by wide margins. The opposite trend is seen in Greenland, with a wide margin in the NE and narrow margins elsewhere. The thin crust beneath the basins is generally underlain by rocks with velocities of .7 km s 21 interpreted as serpentinized mantle in the Porcupine and southern Rockall basins; while off Norway, alternative interpretations such as eclogite bodies and underplating are also discussed.Gold Open Access: This article is published under the terms of the CC-BY 3.0 license.

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The evolution of the Porcupine and Rockall basins, offshore Ireland: the geological template for carbonate mound development

Shannon

McDonnell

Bailey

2006

Int J Earth Sci (Geol Rundsch)

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The margins of the deep-water sedimentary basins west of Ireland contain a number of large clusters (provinces) of spectacular carbonate mounds and build-ups. These basins have a complex development history involving the interplay of rift tectonics, thermal subsidence, igneous activity and oceanographic variations. The Porcupine and Rockall basins both rest upon thin continental crust, the consequence of major rift episodes in Permo-Triassic, Late Jurassic and Early Cretaceous times. Phases of volcanism occurred in the Early Cretaceous and especially in the Early Cenozoic. Fluid flow within the basins is likely to have been controlled by the overall basin geometry and by the distribution and linkage of permeable strata with fault systems, stratal surfaces and unconformities. A number of regional unconformities, controlled by both basin tectonic and regional oceanographic effects, can be mapped and correlated throughout the Porcupine and Rockall basins. The youngest of these unconformities (C10: Early Pliocene) can be traced throughout much of the NW European Atlantic margin. It forms the horizon on which virtually all the carbonate mounds in the basins develop, suggesting a geologically instantaneous mound nucleation and growth event. Although the control on their development is uncertain, the mound clusters show a spatial association with lithified strata, buried contourite and deltaic deposits, slope failure features and with the basin margins. Analysis of these relationships points to a combination of geological and oceanographic processes controlling mound initiation and growth.

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The velocity structure of the sediments in the southern Rockall Basin: results from new wide-angle seismic modelling

Cited by 19 publications

References 17 publications

Three-dimensional gravity and magnetic modelling of the Irish sector of the NE Atlantic margin

Three-dimensional gravity and magnetic modelling of the Irish sector of the NE Atlantic margin

A review of the NE Atlantic conjugate margins based on seismic refraction data

The evolution of the Porcupine and Rockall basins, offshore Ireland: the geological template for carbonate mound development

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