none 10.1144/SP557-2023-212 Geological Society of London Geological Society of London 1881 168758006 65091 2026030408282300243 10.1144 2026-03-04T16:28:37Z 2024-12-12T11:48:25Z 2 Geological Society, London, Special Publications Special Publications 0305-8719 2041-4927 12 11 2024 02 2026 557 1 J. Kim Welford Department of Earth Sciences St. John's, Canada Memorial University of Newfoundland St. John's, Canada https://orcid.org/0000-0002-5919-5303 Sascha Brune GFZ Helmholtz Centre for Geosciences Potsdam, Germany Institute of Geosciences Potsdam-Golm, Germany University of Potsdam Potsdam-Golm, Germany https://orcid.org/0000-0003-4985-1810 Derek Neuharth Department of Earth Sciences ETH Zürich, Switzerland Geological Institute ETH Zürich, Switzerland https://orcid.org/0000-0003-3621-8186 Michael T. King Department of Earth Sciences St. John's, Canada Memorial University of Newfoundland St. John's, Canada Atlantic Region Subsurface and DCI, Cenovus Energy St. John's, Canada https://orcid.org/0000-0003-4557-2144 The Newfoundland–Irish Atlantic conjugate margin pair hosts more continental ribbons, failed rifts, and unusually sized and oriented sedimentary basins than anywhere else in the modern Atlantic Ocean. These margins also happen to have formed through rifting and break-up of the lithosphere that was involved in Appalachian–Caledonide orogenesis in the Paleozoic, with the Mesozoic propagating rift having impinged on the orogenic structures at an oblique angle. Here we combine results from 3D numerical modelling of oppositely propagating rifts, which are superimposed on deformable plate reconstructions of the southern North Atlantic. We propose that the rift oddities of the Newfoundland–Irish Atlantic conjugate margin pair resulted from the northward propagating rift responsible for the break-up of Pangaea reactivating Appalachian–Caledonide inherited structures under extension, effectively turning them into a southward propagating rift. The interaction of the two rifts caused the formation and clockwise rotation of a large continental microplate, which was ultimately split by a transform fault into two smaller clockwise-rotated mirrored continental ribbons, namely the Flemish Cap and the Porcupine Bank. The rotations of these continental microplates, which created the Orphan and Porcupine sedimentary basins and failed rifts therein, show the influence of inherited orogenic structures on subsequent rifting. 02 10 2025 02 2026 111 129 10.1144/SP557-2023-212 1 10.1144/crossmark-policy www.lyellcollection.org true 2023-12-18 2024-04-04 2024-05-06 2025-02-10 Natural Sciences and Engineering Research Council of Canada http://dx.doi.org/10.13039/501100000038 European Research Council http://dx.doi.org/10.13039/501100000781 101087245 http://creativecommons.org/licenses/by/4.0/ 10.1144/SP557-2023-212 https://www.lyellcollection.org/doi/10.1144/SP557-2023-212 https://www.lyellcollection.org/doi/pdf/10.1144/SP557-2023-212 https://pubs.geoscienceworld.org/UrlRedirectHandler.ashx?routename=books&chapterdoi=10.1144/SP557-2023-212&request=chapter 10.1029/2022TC007386 10.1144/SP470.9 10.1029/2011JB008319 10.1029/2012GC004077 10.7289/V5C8276M 10.5281/zenodo.2653531 10.5281/zenodo.8200213 10.1038/s43017-023-00391-3 10.1130/0091-7613(1994)022<0399:TOPMAD>2.3.CO;2 10.1130/0016-7606(2001)113<0443:OICFTL>2.0.CO;2 10.1016/j.marpetgeo.2021.105042 10.1029/2018JB016375 10.1144/jgs2014-139 10.1144/SP470.10 10.1111/bre.12147 10.2973/dsdp.proc.80.158.1985 10.1144/0050501 10.1086/629460 Recorder Enachescu M.E. 5 31 2006 Structural setting and petroleum potential of the Orphan Basin, offshore Newfoundland and Labrador Enachescu, M.E. 2006. Structural setting and petroleum potential of the Orphan Basin, offshore Newfoundland and Labrador. Recorder, 31, 5–13, https://csegrecorder.com/articles/view/structural-setting-and-petroleum-potential-of-orphan-basin-offshore-nfld 10.5724/gcs.05.25.0075 10.1016/j.epsl.2013.11.017 10.1002/2014TC003760 10.1029/2003JB002434 10.5194/se-9-267-2018 10.1038/s41467-021-24945-5 10.1111/bre.12078 10.1007/s00531-016-1341-0 10.1130/DNAG-GNA-I1.239 10.1016/j.cageo.2018.04.007 10.1139/e98-075 10.1029/2020GC009577 10.1093/gji/ggx195 10.1029/2019TC005578 10.1111/j.1365-246X.2006.02800.x 10.1144/SP282.3 10.1051/bsgf/2021043 10.1029/2020JB019906 10.4095/321854 10.1139/e85-133 10.1029/2022GC010372 10.1029/2022GC010373 10.1029/2020TC006467 10.1130/DNAG-GNA-M.351 10.1016/0012-821X(78)90101-2 10.1111/j.1365-246X.2012.05609.x 10.1111/j.1365-3121.2004.00590.x 10.1111/j.1365-246X.2006.02988.x 10.1093/gji/ggv261 10.1016/j.epsl.2017.02.043 10.1038/s41561-018-0178-5 10.1016/j.gr.2014.11.004 10.1016/0040-1951(89)90224-2 10.1016/j.gr.2014.08.006 10.1130/2007.1200(21) 10.1130/G40021.1 10.1029/2018GC007584 10.1029/2018TC005462 10.1016/0040-1951(90)90445-E 10.1130/0091-7613(2000)28<1071:PAGTEA>2.0.CO;2 10.1016/j.tecto.2016.01.006 10.1144/petgeo.2.4.353 10.1029/2019GL086611 10.1016/j.gr.2009.08.001 10.1144/0061009 The Geology of Ireland Naylor D. 405 2009 2 Naylor, D. and Shannon, P. 2009. Geology of offshore Ireland. In: Holland, C.H. and Sanders, I.S. (eds) The Geology of Ireland 2nd edn. Dunedin Academic Press, 405–460. Petroleum Geology of Ireland Naylor D. 2011 Naylor, D. and Shannon, P. 2011. Petroleum Geology of Ireland. Dunedin Academic Press, Edinburgh. Naylor D. Shannon P. and Murphy N. 2002. Porcupine–Goban region – a standard structural nomenclature system. Special Publication 1/02 Petroleum Affairs Division Dublin. 10.1029/2020GC009615 10.1002/2017TC004495 10.1144/0016-76492005-079 10.1016/j.earscirev.2019.102902 10.1016/j.earscirev.2022.104148 10.1144/1354-079309-903 10.1016/j.tecto.2022.229273 10.1016/j.gr.2016.06.012 10.1139/e11-049 10.1111/bre.12308 10.1029/2023JB028109 10.1016/j.pepi.2016.11.007 10.1029/2018TC005018 10.4095/105238 Ruffman A. and Van Hinte J. 1973. Orphan Knoll a “chip” off the North American “plate”. Earth Science Symposium on Offshore Eastern Canada Geological Survey of Canada Paper 71-23 407–449. 10.1029/2018TC004962 10.1016/j.earscirev.2023.104568 10.1111/j.1365-246X.2009.04186.x 10.1016/j.earscirev.2019.102975 10.5194/se-14-389-2023 10.1144/gsjgs.148.1.0181 10.1144/0050421 10.2973/dsdp.proc.12.103.1972 10.1029/2018JB017025 10.1144/SP282.4 10.1111/j.1365-2117.1994.tb00085.x 10.1016/0040-1951(90)90442-B 10.1002/gj.1187 10.1144/SP470.4 10.2973/odp.proc.sr.210.101.2007 10.1306/M46497C16 10.1144/SP282.2 10.1130/G4123A.1 10.1144/0070937 10.1130/B25518.1 10.1144/SP327.13 10.1016/S0040-1951(98)00137-1 10.1029/98JB00604 10.1139/e98-053 10.1002/2015TC003882 10.1144/SP470.11 10.1016/j.earscirev.2022.104163 10.1093/gji/ggad448 10.1144/0016-76492011-114 10.1093/gji/ggz575 10.1016/j.earscirev.2022.103931 10.1111/bre.12530 10.2475/ajs.262.10.1137 10.1139/e79-070 10.1139/e84-095 10.1007/978-3-662-01141-6_58 10.1038/211676a0 10.1029/2022JB024687 10.1144/jgs2022-115 10.1029/2020TC006665 10.1144/GSL.MEM.2006.032.01.03 10.5194/se-14-823-2023 10.1111/bre.12642