NE Atlantic continental rifting and volcanic margin formation

Abstract

Deep seismic data from the Hatton-Rockall region, the mid-Norway margin and the SW Barents Sea provide images of the crustal structure that make it possible to estimate the relative amounts of crustal thinning for the Late Jurassic-Cretaceous and Maastrichtian-Paleocene NE Atlantic rift episodes. In addition, plate reconstructions illustrate the relative movements between Eurasia and Greenland back to Mid-Jurassic time. The NE Atlantic rift system developed as a result of a series of rift episodes from the Caledonian orogeny to early Tertiary time. The Late Palaeozoic rifting is poorly constrained, particularly with respect to timing. However, rifted basin geometries, inferred to be of this age, are observed at depth in seismic data on the flanks of the younger rift structures. Intra-continental rifting in Late Jurassic-Cretaceous times caused c. 50–70 km of crustal extension and subsequent Cretaceous basin subsidence from the Rockall Trough-North Sea areas in the south, to the SW Barents Sea in the north. In late Early to early Late Cretaceous times, new rifting occurred in the Rockall Trough and Labrador Sea associated with the northward propagation of North Atlantic sea-floor spreading. When sea-floor spreading was approached in the Labrador Sea the Rockall rift apparently became extinct. The final NE Atlantic rift episode was initiated near the Campanian-Maastrichtian boundary, lasted until continental separation near the Paleocene-Eocene transition, and caused c. 140 km extension. The late syn-rift and the earliest sea-floor spreading periods were affected by widespread igneous activity across a c. 300 km wide zone along the rifted plate boundary. The deep seismic data provide lower-crustal structural geometries that represent boundary conditions for a better mapping and understanding of the extensional thinning of the crust. The crustal geometries question extension estimates previously made from basin subsidence analysis, and aid in the definition of bodies of magmatic underplating beneath the outer volcanic margins.

Break-up and seafloor spreading domains in the NE Atlantic

“…5a). According to Skogseid et al (2000), the Late Palaeozoic rifting is poorly constrained, but the Late Jurassic -Cretaceous rifting caused approximately 50-70 km of crustal extension and subsequent Cretaceous basin subsidence from the Rockall Trough-North Sea areas to the SW Barents Sea. A Late CretaceousPaleocene renewed rifting episode caused approximately 140 km of extension (Skogseid et al 2000).…”

“…Domeier 2015), and subsequent Baltica -Laurentia collision (e.g. Doré et al 1997;Skogseid et al 2000). Seafloor spreading propagated from south to north starting in Cretaceous times in distinct phases that involved the following regions: Newfoundland-Iberia, North America-Porcupine, North America-Greenland (Labrador Sea and Baffin Bay), Greenland -Eurasia and Lomonosov Ridge -Eurasia (Eurasian Basin, Arctic Ocean) ( Fig.…”

The onset of the North Atlantic Igneous Province in a rifting perspective

“…Simplified map of the NAIP at around 62 to 58 Ma modified from and Torsvik, Mosar & Eide (2001). The inferred locations of the Caledonian fronts and the Iapetus suture zone are from: Bott (1987); Soper et al (1992); Ziegler (1992); Masson, Hauser & Jacob (1999); Skogseid et al (2000); Hansen & Brooks (2002); Roberts (2003); Foulger, Natland & Anderson (2005a,b); Cocks (2005). The inferred Archaean-Proterozoic suture zone in the Rockall-Hatton-NW Britain area is modified from Dickin (1992).…”

Oblique rifting: the rule, not the exception

“…Trough, the Porcupine, Orphan, Møre, and Faroe-Shetland Basin (Skogseid et al, 2000;Faleide et al, 2008;Peron-Pinvidic et al, 2013). However, Mesozoic rifting also induced continental breakup in the Iberia-Newfoundland segment, the Bay of Biscay, and the North Atlantic rift south of Greenland (Féraud et al, 1996;Nirrengarten et al, 2018;Tugend et al, 2014).…”