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

Abstract

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract -The processes that led to the onset and evolution of the North Atlantic Igneous Province (NAIP) have been a theme of debate in the past decades. A popular theory has been that the impingement on the lower lithosphere of a hot mantle plume (the 'Ancestral Iceland' plume) initiated the first voluminous outbursts of lava and initiated rifting in the North Atlantic area in Early Palaeogene times. Here we review previous studies in order to set the NAIP magmatism in a time-space context. We suggest that global plate reorganizations and lithospheric extension across old orogenic fronts and/or suture zones, aided by other processes in the mantle (e.g. local or regional scale upwellings prior to and during the final Early Eocene rifting), played a role in the generation of the igneous products recorded in the NAIP for this period. These events gave rise to the extensive Paleocene and Eocene igneous rocks in W Greenland, NW Britain and at the conjugate E Greenland-NW European margins. Many of the relatively large magmatic centres of the NAIP were associated with transient and geographically confined doming in Early Paleocene times prior to the final break-up of the North Atlantic area.

Basin-scale architecture of deeply emplaced sill complexes: Jameson Land, East Greenland

“…5; Larsen & Marcussen 1992;Hald & Tegner 2000). Throughout the North Atlantic Igneous Province it can be shown that there are two main periods of igneous activity, with ages of c. 62 -58 Ma and c. 57 -53 Ma, with detectable peaks at c. 60 Ma and at c. 55 Ma, respectively (Saunders et al 1997;Torsvik et al 2001;Jerram & Widdowson 2005;Hansen et al 2009;Brooks 2011, and references therein). These are often cited as relating to the impingement of the Iceland plume and the main phase of rifting and continental separation (Hansen et al 2009).…”

“…Saunders et al 1997;Hansen et al 2009;Jerram et al 2009;Brooks 2011;Nelson et al 2015). Along East Greenland this opening propagated northwards to the Norwegian-Greenland Sea and led to plate separation occurring during the Eocene (c. 55 Ma), and was accompanied by widespread igneous activity along 2000 km of the conjugate rifted margins (e.g.…”

Lateral Magma Flow in Mafic Sill‐complexes

“…62-53 Ma in response to the break-up of the North Atlantic and the impingement of a mantle plume at the base of the lithosphere (White and McKenzie, 1989;Saunders et al, 1997;Kent and Fitton, 2000;Emeleus and Bell, 2005;Storey et al, 2007;Hansen et al, 2009). Age relationships and radiometric dating suggest that the North Atlantic Igneous Province can be divided into two main phases of magmatic activity; one between ca.…”

“…Voluminous sill complexes, dike swarms, volcanic centers, and extrusive igneous rocks, primarily of basaltic composition, were emplaced during these phases (~6.6 × 10 6 km 2 in total) and are located along two volcanic rifted margins; the conjugate east Greenland-northwest European and the west Greenland-Baffin Bay margins ( Fig. 2; Storey et al, 2007;Hansen et al, 2009). …”

Mafic intrusions, hydrothermal venting, and the basalt-sediment transition: Linking onshore and offshore examples from the North Atlantic igneous province

“…Continental break-up in the North Atlantic region between northwest Europe and East Greenland during the Palaeogene was accompanied by widespread volcanism associated with NAIP (e.g., Saunders et al, 1997;Hansen et al, 2009). Extensive lava fields, hydrovolcanic sequences, and subsurface intrusive complexes were emplaced on either side of the developing continental rift zone from the Late Paleocene to the Early Eocene followed by seafloor spreading.…”