Elsevier

Journal of Geodynamics

Volume 128, July 2019, Pages 11-37
Journal of Geodynamics

Deformable plate tectonic models of the southern North Atlantic

https://doi.org/10.1016/j.jog.2019.05.005Get rights and content

Abstract

Significant, poly-phase deformation occurred prior to, simultaneous with, and after the opening of the North Atlantic Ocean. Understanding this deformation history is essential for understanding the regional development and the mechanisms controlling rifting and subsequent failure or breakup. Here, we primarily use published constraints to construct deformable plate tectonic models for the southern North Atlantic from 200 Ma to present using GPlates. The aim of this work is to test both the capability of the GPlates deformable modelling approach and the reliability of published plate reconstructions. Overall, modelled crustal thickness values at 0 Ma produced from the deformable models show general, regional-scale, similarities with values derived from the inversion of gravity data for crustal thickness. However, the deformable models typically underestimate thinning in marginal basins and overestimate crustal thickness in continental fragments compared to values from gravity inversion. This is possibly due to: 1) thinning occurring earlier than the 200 Ma start time modelled, 2) variations in the original crustal thickness, 3) depth-dependent stretching, 4) rigid blocks undergoing some degree of thinning, and 5) variations in the mesh density of the models. The results demonstrate that inclusion of micro-continental fragments, and locally defined limits of continental crust, generally produce results more akin to observations. One exception is the Grand Banks where global GPlates models produce more realistic deformation, likely due to the inclusion of the exhumed domains continent-ward of the transition zone boundary. Results also indicate that Flemish Cap rotation is required to provide a reasonable fit between North America and Iberia, with the palaeo-position of the Flemish Cap likely to be the proto-Orphan sub-basins. Moreover, the East and West Orphan sub-basins formed separately due to the respective rotations of the Flemish Cap and the Orphan Knoll, which was likely associated with other continental fragments that subsequently contributed to the thicker crust forming the boundary between the East and West Orphan basins. The results also suggest a link between tectonic and magmatic processes. For example, the inclusion of an Orphan Knoll micro-continental block results in greater extension (higher beta factors) in the northern West Orphan Basin near the termination of the Charlie-Gibbs Fracture Zone, and the site of the Charlie-Gibbs Volcanic Province (CGVP). Thus, we infer that the CGVP was likely influenced by plate tectonic processes through the concentration of strain resulting from interaction in proximity to the transform system. Finally, marginal basins that were considered to be conjugate and thus related, may only appear conjugate through later rotation of micro-continental blocks, and thus their genesis is not directly related.

Introduction

The opening of the modern North Atlantic Ocean represents the final dispersal and end of the Laurasia continental amalgamation that formed the northern portion of the Pangaea supercontinent (Gaina et al., 2009; Hansen et al., 2009; Frizon De Lamotte et al., 2015; Peace et al., 2019) (Fig. 1). The ocean is divided into two main spreading branches; the Northeast Atlantic between Greenland and Europe, and the Labrador Sea – Baffin Bay system between Greenland and North America (Srivastava, 1978; Beniest et al., 2017), that form a complex junction with the northeast Atlantic to the north of the Charlie-Gibbs Fracture Zone (CGFZ) (Gaina et al., 2009).

In addition to the primary breakup axes, complex styles of deformation occurred on the continental margins, including the preservation of relatively undeformed continental fragments (Peron-Pinvidic and Manatschal, 2010; Peron-Pinvidic et al., 2012a, 2012b; Nirrengarten et al., 2018; Schiffer et al., 2018), continental transform systems (e.g., the Davis Strait; Suckro et al., 2013; Peace et al., 2018b), and multiple failed rift axes (e.g., the North Sea; Rattey and Hayward, 1993). Despite the significant role that such deformation had upon the geological evolution of the continental margins, including the prospective petroliferous basins, plate tectonic reconstructions often struggle to account for much of this deformation prior to breakup (Ady and Whittaker, 2018). For this reason, it is the deformation in these continental rifted margins and basins, including the driving mechanisms, that form the focus of this study.

Here, we primarily use published constraints (e.g., Müller et al., 2016; Matthews et al., 2016; Nirrengarten et al., 2018; Welford et al., 2018) to construct deformable plate tectonic models for the southern North Atlantic using the open source GPlates environment (Williams et al., 2012a; Gurnis et al., 2018; Müller et al., 2018). We then compare the results obtained from the deformable models with both geological and geophysical observations including: crustal structure derived through gravity inversion (Welford et al., 2012; Roberts et al., 2018), regional seismic reflection lines (e.g., Tucholke et al., 2007; Tucholke and Sibuet, 2007), the age of syn-rift strata in passive margin rift basins (e.g., Gouiza et al., 2016), documented inversion (e.g., Yang, 2012), and occurrences of rift-related magmatism (e.g., Keen et al., 2014). The aim of this analysis was to investigate: 1) the reliability of published constraints as model components; 2) the reliability and applicability of the current generation of GPlates deformable models to reproduce realistic passive margin deformation, and 3) the implications for the spatio-temporal evolution of the region, including the consequences for magmatism, conjugate margin, and connected basin studies.

Section snippets

Geological setting: The southern North Atlantic

In this study, the southern North Atlantic (Fig. 1) includes the conjugate Newfoundland-Iberia margins to the south and extends as far north as the southern Labrador Sea, southeast Greenland and the conjugate northwest European margin south of Iceland, approximately the same study area as that of Nirrengarten et al. (2018). This study area was chosen as the large-scale post-breakup plate movements are well constrained from studies of the oceanic crust (e.g., Barnett-Moore et al., 2018) and

Reconstructions of the southern North Atlantic: the need for deformable plate tectonic models

Many plate tectonic models and reconstructions have been produced for the Mesozoic-Cenozoic rifting and breakup of the North Atlantic region (Bullard et al., 1965; Rowley and Lottes, 1988; Dunbar and Sawyer, 1989; Hosseinpour et al., 2013; Barnett-Moore et al., 2018; Nirrengarten et al., 2018). Each of these models inherently comes with its own assumptions, simplifications and omissions, depending on the scientific question being evaluated. Many, but not all (e.g., Whittaker and Ady, 2011; Ady

Crustal thickness, evolution, and beta factors

The evolution of crustal thickness through time in all models shows general similarities as the large-scale movement of the major plates (i.e. North America, Greenland, Iberia and Eurasia) are ultimately driven by similar poles of rotation (e.g., Barnett-Moore et al., 2018). However, the small (basin) scale manifestations of deformation are highly variable. Implications for this deformation form the focus of this study and are more susceptible to minor variations in model inputs such as

Comparison between deformable model results and regional observations

In this section, the results of the GPlates deformable models (Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14) are compared to geological and geophysical observations from across the modelled region, principally the gravity inversion results from Welford et al. (2012) (Fig. 15), but also other observations such as the interpretation of seismic reflection data (e.g., Yang, 2012; Keen et al., 2014; Gouiza et al., 2016). This was undertaken to test whether the various

Conclusions

A suite of deformable plate tectonic models based on published constraints for the southern North Atlantic has been created in GPlates. The purpose was to test the viability of the GPlates deformable modelling approach, the published model inputs, and the influence of various pre-rift configurations. The conclusions of this study are as follows:

  • 1)

    The GPlates deformable modelling tool has proven to be an effective means of testing different scenarios for the tectonic development of the southern

Acknowledgements

Alexander L. Peace’s postdoctoral fellowship at Memorial University of Newfoundland was funded by the Hibernia Project Geophysics Support Fund and Innovate NL. We would like to thank the GPlates development and maintenance team and the members of the MAGRiT group at Memorial University of Newfoundland for valuable scientific discussions. We would also like to acknowledge TGS for the generous provision of the seismic reflection data from the Orphan Basin. To prevent visual distortion of the

References (165)

  • L. Geoffroy

    Volcanic passive margins

    Comptes Rendus – Geosci.

    (2005)
  • M. Gurnis et al.

    Plate tectonic reconstructions with continuously closing plates

    Comput. Geosci.

    (2012)
  • M. Gurnis et al.

    Global tectonic reconstructions with continuously deforming and evolving rigid plates

    Comput. Geosci.

    (2018)
  • K. Hitchen

    The geology of the UK Hatton-Rockall margin

    Mar. Pet. Geol.

    (2004)
  • S. Leleu et al.

    Structural, stratigraphic and sedimentological characterisation of a wide rift system: the Triassic rift system of the Central Atlantic Domain

    Earth. Rev.

    (2016)
  • F. Marillier et al.

    LITHOPROBE East onshore-offshore seismic refraction survey -constraints on interpretation of reflection data in the Newfoundland Appalachians

    Tectonophysics

    (1994)
  • K.J. Matthews et al.

    Global plate boundary evolution and kinematics since the late Paleozoic

    Glob. Planet. Change

    (2016)
  • D. McKenzie

    Some remarks on the development of sedimentary basins

    Earth Planet. Sci. Lett.

    (1978)
  • Bridget E. Ady et al.

    Examining the influence of tectonic inheritance on the evolution of the North Atlantic using a palinspastic deformable plate reconstruction

    Geol. Soc. London Spec. Publ.

    (2018)
  • T.M. Alves et al.

    Deep-water continental margins: geological and economic frontiers

    Basin Res.

    (2014)
  • N. Ammann et al.

    Oblique continental rifting and long transform fault formation based on 3D thermomechanical numerical modeling

    Tectonophysics

    (2017)
  • S.G. Archer et al.

    Palaeogene igneous rocks reveal new insights into the geodynamic evolution and petroleum potential of the Rockall Trough, NE Atlantic Margin

    Basin Res.

    (2005)
  • D. Ashby

    Influences on continental margin development: a case study from the Santos Basin, South-eastern Brazil

    (2013)
  • P. Ball et al.

    The spatial and temporal evolution of strain during the separation of Australia and Antarctica

    Geochem. Geophys. Geosystems

    (2013)
  • N. Barnett-Moore et al.

    A reconstruction of the North Atlantic since the earliest Jurassic

    Basin Res.

    (2018)
  • A. Beniest et al.

    Two-branch break-up systems by a single mantle plume: insights from numerical modeling

    Geophys. Res. Lett.

    (2017)
  • E.K. Beutel

    Stress-induced seamount formation at ridge-transform intersections

    Geol. Soc. Am. Spec. Pap.

    (2005)
  • A. Blischke et al.

    The structural history of the Jan Mayen micro-continent (JMMC) and its role during the rift “Jump” between the Aegir to the Kolbeinsey Ridge *

  • E. Bullard et al.

    The fit of the continents around the Atlantic: philosophical transactions of the royal society a: mathematical

    Phys. Eng. Sci.

    (1965)
  • P. Cadenas et al.

    Constraints imposed by rift inheritance on the compressional reactivation of a hyperextended margin: mapping rift domains in the north Iberian margin and in the Cantabrian mountains

    Tectonics

    (2018)
  • G. Calvès et al.

    New evidence for the origin of the Porcupine Median Volcanic Ridge: Early Cretaceous volcanism in the Porcupine Basin, Atlantic margin of Ireland

    Geochem. Geophys. Geosystems

    (2012)
  • C. Chen et al.

    From continental hyperextension to seafloor spreading: new insights on the Porcupine Basin from wide-angle seismic data

    J. Geophys. Res. Solid Earth

    (2018)
  • D. Chian et al.

    Evolution of nonvolcanic rifted margins: new results from the conjugate margins of the Labrador Sea

    Geology

    (1995)
  • D.B. Clarke et al.

    Davis Strait Paleocene Picrites: Products of a Plume or Plates?

    Earth. Rev.

    (2019)
  • S. Cloetingh et al.

    Post-rift compressional reactivation potential of passive margins and extensional basins

    Geol. Soc. London Spec. Publ.

    (2008)
  • F. Crameri

    Geodynamic diagnostics, scientific visualisation and StagLab 3.0

    Geosci. Model. Dev.

    (2018)
  • L.T. Dafoe et al.

    Regional stratigraphy and subsidence of Orphan Basin near the time of breakup and implications for rifting processes

    Basin Res.

    (2017)
  • A.G. Doré et al.

    Cenozoic compressional structures on the NE Atlantic margin; nature, origin and potential significance for hydrocarbon exploration

    Pet. Geosci.

    (1996)
  • A.G. Doré et al.

    Principal tectonic events in the evolution of the northwest European Atlantic margin: petroleum geology of Northwest Europe

    Proceedings of the 5th Conference

    (1999)
  • A.G. Doré et al.

    Potential mechanisms for the genesis of Cenozoic domal structures on the NE Atlantic margin: pros, cons and some new ideas

    Geol. Soc. London Spec. Publ.

    (2008)
  • M. Druet et al.

    Crustal structure and continent‐ocean boundary along the Galicia continental margin (NW Iberia): insights from combined gravity and seismic interpretation

    Tectonics

    (2018)
  • J.A. Dunbar et al.

    Patterns of continental extension along the conjugate margins of the central and North ATLANTIC Oceans and Labrador Sea

    Tectonics

    (1989)
  • M.P. Eddy et al.

    Timing of initial seafloor spreading in the Newfoundland-Iberia rift

    Geology

    (2017)
  • M.E. Enachescu

    Structural setting and petroleum potential of the Orphan Basin, offshore Newfoundland and Labrador

    Can. Soc. Explor. Geophys. Record.

    (2006)
  • J. Engström et al.

    Continental collision structures and post-orogenic geological history of the Kangerlussuaq area in the Southern Part of the Nagssugtoqidian Orogen, Central West Greenland

    Geosciences

    (2014)
  • G.‐P. Farangitakis et al.

    Analogue modeling of plate rotation effects in transform margins and rift‐transform intersections

    Tectonics

    (2019)
  • G.R. Foulger et al.

    The Yellowstone “hot spot” track results from migrating basin-range extension

    Geol. Soc. Am. Spec. Pap.

    (2015)
  • D. Frizon De Lamotte et al.

    Style of rifting and the stages of Pangea breakup

    Tectonics

    (2015)
  • T. Funck

    Crustal structure of the ocean-continent transition at Flemish Cap: seismic refraction results

    J. Geophys. Res.

    (2003)
  • C. Gaina et al.

    Palaeocene-Recent plate boundaries in the NE Atlantic and the formation of the Jan Mayen microcontinent

    J. Geol. Soc.

    (2009)
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