No abstract

eeD eFvF nd hethenD tFtFtF nd prnkeD hF nd poulgerD qFF nd hi'erD gF nd elfordD tFuF nd wroneD qF nd ohiD F nd hnelD wF nd hor¡ eD eFqF @PHIWA 9e review of nge dispersl nd vrge sgneous rovines ! in serh of ustive mehnismF9D irthEsiene reviewsFD IWT F pF IHPVTSF

Intraplate basin/structural inversion (indicating tectonic shortening) is a good marker of ("far-field") tectonic stress regime changes that are linked to plate geometries and interactions, a premise that is qualitatively well-established in the literature. There is also quantitative evidence that Late Cretaceous-Palaeocene inversion of sedimentary basins in north-central Europe was explicitly driven by an intraplate, relaxational response to forces developed during rapid reconfigurations of the Alpine-Tethys (Europe-Africa) convergent plate boundary. Although with a degree of temporal ambiguity, three main periods of intraplate tectonics (marked primarily by structural inversion in initially extensional sedimentary basins) are indicated in the North Atlantic-western Alpine-Tethys realm. These are in the Late Cretaceous-Palaeocene, the Eocene-Oligocene and the Miocene. Examples recording these periods are primarily interpreted seismic reflection profiles (of varying quality and resolution) from the published literature. Additional examples where seismic data are not present, but timing constraints are robust from other observations, have also been considered. The schematic distribution and orientation of the literature-compiled intraplate inversion structures are compared to the model palaeostress fields derived from Late Cretaceous-Palaeocene, Eocene-Oligocene and Miocene tectonic reconstructions of the North Atlantic-western Alpine-Tethys realm. The modelled palaeostress fields include geopotential effects from palaeobathymetry and palaeotopography of the Earth's surface as well as laterally variable lithosphere and crustal palaeothicknesses but do not include any component of the stress field produced by processes occurring at contiguous convergent plate margins. The former satisfactorily provides the background stress field of most of the Earth's plate interiors and it is inferred that the latter is paramount in producing "stress trauma" in the interior of plates resulting in permanent intraplate deformation such as basin inversion.

Reconstructions of the opening of the North Atlantic Ocean generally result in the Orphan Basin, offshore Newfoundland, Canada, lying approximately conjugate to the rift basins on the Irish Atlantic margin at the onset of seafloor spreading toward the end of the Early Cretaceous. Most of these plate reconstructions have involved rigid plates with plate motions based solely on the interpretation of oceanic magnetic anomalies. In particular, these reconstructions often show the Rockall Basin, west of Ireland, forming a continuous Mesozoic basin with the West Orphan Basin, offshore Newfoundland. However, more recent plate reconstructions involving deformable plates have called this conjugate relationship into question. The goal of this study is to investigate the validity of this potentially continuous basin system by reconstructing and restoring present-day seismically-constrained geological models both spatially and temporally back to their original configurations pre-rift. By comparing the reconstructions in terms of sedimentary package thicknesses and crustal thicknesses in 3D, using both rigid and deformable plate reconstructions to orient the reconstructed models, we are able to test different basin connectivity scenarios using a multidisciplinary approach. Our analysis provides subsurface geophysical support for the hypothesis that the Rockall Basin was originally conjugate to and continuous with the East Orphan Basin during Jurassic rifting, later linking to the West Orphan Basin as rifting evolved during the Early Cretaceous. This complex basin evolution example highlights the need for using 3D rifting mechanism models to properly understand the fundamental driving forces during rifting and has significant implications for assessing basin prospectivity across conjugate margin pairs.