Rapid Spatiotemporal Variations in Rift Structure During Development of the Corinth Rift, Central Greece Casey W
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Rapid spatiotemporal variations in rift structure during development of the Corinth Rift, central Greece Casey W. Nixon, Lisa C. Mcneill, Jonathan M. Bull, Rebecca E. Bell, Robert L. Gawthorpe, Timothy J. Henstock, Dimitris Christodoulou, Mary Ford, Brian Taylor, Dimitris Sakellariou, et al. To cite this version: Casey W. Nixon, Lisa C. Mcneill, Jonathan M. Bull, Rebecca E. Bell, Robert L. Gawthorpe, et al.. Rapid spatiotemporal variations in rift structure during development of the Corinth Rift, central Greece. Tectonics, American Geophysical Union (AGU), 2016, 35 (5), pp.1225-1248. 10.1002/2015TC004026. hal-01416610 HAL Id: hal-01416610 https://hal.archives-ouvertes.fr/hal-01416610 Submitted on 13 Aug 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License PUBLICATIONS Tectonics RESEARCH ARTICLE Rapid spatiotemporal variations in rift structure during 10.1002/2015TC004026 development of the Corinth Rift, central Greece Key Points: Casey W. Nixon1,2, Lisa C. McNeill1, Jonathan M. Bull1, Rebecca E. Bell3, Robert L. Gawthorpe2, • Offshore Corinth Rift evolution is 1 4 5 6 7 investigated at high spatial and Timothy J. Henstock , Dimitris Christodoulou , Mary Ford , Brian Taylor , Dimitris Sakellariou , 4 4 8 9 temporal resolution George Ferentinos , George Papatheodorou , Mike R. Leeder , Richard E.LI. Collier , • Rift migration and localization of Andrew M. Goodliffe10, Maria Sachpazi11, and Haralambos Kranis12 deformation are significant within the Corinth Rift 1National Oceanography Centre Southampton, University of Southampton, Southampton, UK, 2Department of Earth • Changes in rift geometry and linkage 3 of major rift faults occur at rapid 100 Science, University of Bergen, Bergen, Norway, Department of Earth Science & Engineering, Imperial College London, 4 5 kyr timescales London, UK, Department of Geology, University of Patras, Patras, Greece, CRPG-CNRS, University of Nancy, Nancy, France, 6School of Ocean and Earth Science and Technology, University of Hawai‘i, Honolulu, Hawaii, USA, 7Hellenic Centre for Marine Research, Anavissos, Greece, 8School of Environmental Sciences, University of East Anglia, Norwich, UK, 9School of Supporting Information: 10 • Supporting Information S1 Earth and Environment, University of Leeds, Leeds, UK, Department of Geological Sciences, University of Alabama, Tuscaloosa, Alabama, USA, 11National Observatory of Athens, Athens, Greece, 12Dynamic, Tectonic and Applied Geology, Correspondence to: National and Kapodistrian University of Athens, Athens, Greece C. W. Nixon, [email protected] Abstract The Corinth Rift, central Greece, enables analysis of early rift development as it is young (<5Ma) and highly active and its full history is recorded at high resolution by sedimentary systems. A complete Citation: Nixon, C. W., et al. (2016), Rapid compilation of marine geophysical data, complemented by onshore data, is used to develop a high-resolution spatiotemporal variations in rift chronostratigraphy and detailed fault history for the offshore Corinth Rift, integrating interpretations and structure during development of the reconciling previous discrepancies. Rift migration and localization of deformation have been significant within Corinth Rift, central Greece, Tectonics, 35, 1225–1248, doi:10.1002/ the rift since inception. Over the last circa 2 Myr the rift transitioned from a spatially complex rift to a uniform 2015TC004026. asymmetric rift, but this transition did not occur synchronously along strike. Isochore maps at circa 100 kyr intervals illustrate a change in fault polarity within the short interval circa 620–340 ka, characterized by Received 9 SEP 2015 progressive transfer of activity from major south dipping faults to north dipping faults and southward migration Accepted 22 MAR 2016 Accepted article online 18 MAY 2016 of discrete depocenters at ~30 m/kyr. Since circa 340 ka there has been localization and linkage of the dominant Published online 24 MAY 2016 north dipping border fault system along the southern rift margin, demonstrated by lateral growth of discrete depocenters at ~40 m/kyr. A single central depocenter formed by circa 130 ka, indicating full fault linkage. These results indicate that rift localization is progressive (not instantaneous) and can be synchronous once a rift border faultsystemisestablished.Thisstudyillustratesthatdevelopmentprocesseswithinyoungriftsoccurat100kyr timescales, including rapid changes in rift symmetry and growth and linkage of major rift faults. 1. Introduction Over the past 20 years, numerous studies of synrift deformation have furthered our knowledge of fault and rift evolution, e.g., North Sea [Fossen and Hesthammer, 1998; Cowie et al., 2005; Bell et al., 2014], Gulf of Corinth Rift [e.g., Taylor et al., 2011; Ford et al., 2013], East African Rift [Hayward and Ebinger, 1996], Rio Grande Rift [Leeder and Mack, 2009], Gulf of Suez [Gawthorpe et al., 2003], and Gulf of California [Aragón-Arreola et al., 2005]. Studies of these evolving and mature rifts have recognized progressive strain localization as an important process in rift evolution on a variety of temporal and spatial scales. It is commonly thought that rifts develop an initially broad zone of complex deformation that becomes localized onto a smaller number of discrete and increasingly large faults [Walsh et al., 2001; Cowie et al., 2005], while sedimentation becomes focused into fewer, larger depocenters [Gawthorpe and Leeder, 2000; Gawthorpe et al., 2003; Cowie et al., 2007]. Furthermore, it has been shown that active faulting and strain migrate toward the rift axis with increasing extension, resulting in rift narrowing [Gawthorpe et al., 2003; Cowie et al., 2005]. Localization of deformation has also been predicted by both physical [e.g., Ackermann et al., 2001; Mansfield and Cartwright, 2001] and numerical models [e.g., Gupta ©2016. The Authors. et al., 1998; Behn et al., 2002; Huismans and Beaumont, 2007]. This is an open access article under the terms of the Creative Commons Models of rift evolution are typically based on mature rifts and passive margins, where the first few million years Attribution License, which permits use, of rift history are unresolved. Most studies have only achieved rift-scale temporal resolutions of the order of distribution and reproduction in any > fi medium, provided the original work is 1 Myr due to reliance on eld observations (e.g., Gulf of Suez) [Gawthorpe et al., 2003] or deep offshore basins properly cited. (e.g., North Sea) [Cowie et al., 2005]. Some studies have investigated the evolution of individual fault systems at NIXON ET AL. RAPID CHANGES IN RIFT STRUCTURE, CORINTH 1225 Tectonics 10.1002/2015TC004026 Figure 1. Structural map of the Corinth Rift, illustrating the new and refined offshore fault network interpreted in this study. Inset is a location map of the Corinth Rift within the tectonic framework of the Aegean. All major active faults offset 100 kyr horizon (see Figure 3). Onshore faults are after Ford et al. [2008] in the west, Skourtsos and Kranis [2009] for the central rift, and Collier and Dart [1991] and Freyberg [1973] in the east. Offshore faults in the Trizonia Basin are after Beckers et al. [2015]. Bathymetry data courtesy of the Hellenic Centre for Marine Research collected for R/V Aegaeo cruises [Sakellariou et al., 2007]. finer spatial and temporal scale (tens of kiloyears); however, these studies have been restricted to recent activity only or are not at rift scale [e.g., Morley et al., 2000; Hemelsdaël and Ford, 2014; Nixon et al., 2014]. Therefore, details of variations in structural style, strain distribution, and strain rate at high resolution (temporal resolution of 104–106 years and spatial resolution of one to tens of kilometers) at whole rift scale are rarely resolved. The Corinth Rift (Figure 1) initiated < 5Ma[Ori, 1989] and is one of the most rapidly extending (10–16 mm/yr) [Bernard et al., 2006; Clarke et al., 1998; Briole et al., 2000] active rift systems on Earth today. The rift itself is significantly smaller (~100 km × ~40 km) than other rifts (e.g., East African Rift; Basin and Range) and therefore can be investigated in its entirety at high resolution. The rift has a simple history of N-S extension [McKenzie, 1972; Roberts and Jackson, 1991] and has not been magmatically overprinted. Hence, this rift is an ideal natural laboratory for investigating the early development of marine/lacustrine rift basins and rifted margins. The Corinth Rift has been studied extensively both onshore [e.g., Gawthorpe et al., 1994; Leeder et al., 2002, 2012; Roberts et al., 2009; Ford et al., 2013] and offshore [e.g., Stefatos et al., 2002; Sachpazi et al., 2003; Leeder et al., 2005; McNeill et al., 2005; Lykousis et al., 2007; Sakellariou et al., 2007; Bell et al., 2008, 2009, 2011; Taylor et al., 2011; Charalampakis et al., 2014; Beckers et al., 2015] to extract synrift sedimentation, fault and rift architecture, and to quantify extension. However, the existing