Passive margin inversion controlled by stability of the mantle lithosphere

Auzemery, Antoine; Willingshofer, Ernst; Sokoutis, Dimitrios; Brun, Jean‐Pierre; Cloetingh, S.A.P.L.

doi:10.1016/j.tecto.2021.229042

Cited by 15 publications

(12 citation statements)

References 138 publications

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“…First we note that, the level of integrated stress required for subduction initiation depends mainly on the strength of the continental lithosphere that depends largely on its composition, thermal regime and the presence of weakening mechanisms (Cloetingh et al, 2005) and fluids (Regenauer-Lieb et al, 2001). In our study, the stress limit also varies with rheological layering and thermal state at the margin (Auzemery et al, 2021) and the earlier mentioned 20 TN/m limit is only valid for a 4 layer-160 km thick-continental lithosphere. This explains differences with similar studies (e.g., Zhong and Li, 2019), in which the crust is weaker and thermal thickness at the margin is significantly smaller than in our models.…”

Section: Driving and Resisting Factorsmentioning

confidence: 52%

Kinematic Boundary Conditions Favouring Subduction Initiation at Passive Margins Over Subduction at Mid-oceanic Ridges

2021

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We perform numerical modelling to simulate the shortening of an oceanic basin and the adjacent continental margins in order to discuss the relationship between compressional stresses acting on the lithosphere and the time dependent strength of the mid-oceanic ridges within the frame of subduction initiation. We focus on the role of stress regulating mechanisms by testing the stress–strain-rate response to convergence rate, and the thermo-tectonic age of oceanic and continental lithospheres. We find that, upon compression, subduction initiation at passive margin is favoured for thermally thin (Palaeozoic or younger) continental lithospheres (<160 km) over cratons (>180 km), and for oceanic basins younger than 60 Myr (after rifting). The results also highlight the importance of convergence rate that controls stress distribution and magnitudes in the oceanic lithosphere. Slow convergence (<0.9 cm/yr) favours strengthening of the ridge and build-up of stress at the ocean-continent transition allowing for subduction initiation at passive margins over subduction at mid-oceanic ridges. The results allow for identifying geodynamic processes that fit conditions for subduction nucleation at passive margins, which is relevant for the unique case of the Alps. We speculate that the slow Africa–Europe convergence between 130 and 85 Ma contributes to the strengthening of the mid-oceanic ridge, leading to subduction initiation at passive margin 60–70 Myr after rifting and passive margin formation.

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Section: Driving and Resisting Factorsmentioning

confidence: 52%

Kinematic Boundary Conditions Favouring Subduction Initiation at Passive Margins Over Subduction at Mid-oceanic Ridges

2021

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“…Among the rare examples of reactivated passive margins, the Algerian margin case study has received a peculiar attention in the last 20 years. Indeed, this margin illustrates a typical case of a weak mantle lithosphere with short length-scales of deformation (Hamai et al, 2015;Auzemery et al, 2021) and locates at a diffuse plate boundary which absorbs most of the slow convergence between Africa and Europe (Palano et al, 2015;Bougrine et al, 2019;Serpelloni et al, 2022;Billi et al, 2023), producing rare but strong, sometimes damaging earthquakes (Hamdache et al, 2010;Bellalem et al, 2022). The 1856The , 1954The , 1980The and 1985 earthquakes (Figure 1) are among the main historical and instrumental earthquakes worth to mention.…”

Section: Introductionmentioning

confidence: 90%

“…By contrast, the tectonic reactivation of passive margins leads to much more tenuous witnesses of faulting and folding at the ocean-continent transition, at least in early stages, owing to the highly variable autogenic and allogenic controls on submarine landscapes (Pratson et al, 2007;Pettinga and Jobe, 2021) in a context of comparatively lower strain rates and widespread deformation (e.g. Auzemery et al, 2021;Somoza et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

A submarine morphotectonic analysis combining GIS-based methods and virtual reality: Case study of the low-rate active thrust faulting off Boumerdès (Algeria)

Déverchère¹,

Barbé²,

Kernec³

et al. 2022

Front. Earth Sci.

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The Algerian margin is located at the slow-rate convergent boundary between African and Eurasian plates and experienced several strong earthquakes in the last centuries. Among them, the 2003 Mw 6.8 Boumerdès event has triggered large turbidity currents in the slightly concave canyons of the slope and numerous cable breaks in the abyssal plain. In this study, we explore where, how and when the tectonic inversion of the margin off Boumerdès has left witnesses in the seafloor morphology and whether the observed deformation correlates with the 2003 coseismic rupture zone and with the Plio-Quaternary sedimentation. We have performed a careful analysis of the seafloor morphology and subsurface seismic reflectors at the landscape scale and along/between canyons by combining classical GIS-based methods and Virtual Reality techniques. From the mid-slope to the deep basin off the ∼60 km long Boumerdès-Dellys coast, we evidence large knickpoints corresponding to the development of four main cumulative fault scarps and two perched basins which are deeply incised by steep canyons and gullies. We interpret these structures to result from frontal propagation of two main south-dipping thrusts by upper crustal décollement ramping, evidencing an incipient sub-thrust imbrication in a stage of initiation of an accretionary wedge. The flat-ramp thrust geometry and their along-strike segmentation explain the development and shape of the perched basins in the backlimb of fault-related folds. The onset of growth strata is dated at 1.5 ± .5 Ma on the slope and .9 ± .3 Ma in the deep basin. The length, position, strike and segmentation of the older, southern thrust ramp are consistent with the coseismic characteristics of the Mw 6.8 2003 earthquake. The cumulative vertical scarp throw exceeds 1 km, supporting Quaternary shortening rates of 1.6 ± .7 mm/yr, in agreement with geodetic strain rates across the western Mediterranean basin. Virtual Reality offers powerful and promising means to correlate seismic imagery and seafloor morphology and is of great help to improve the robustness of tectonostratigraphic interpretation.

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“…Nevertheless, numerical modelling studies have continued to search for potential sites for future subduction at present-day passive margins, such as the mechanically weak southern Brazilian margin (Nikolaeva et al, 2011;Marques et al, 2013), the Argentine Basin and the U.S. East Coast, which are likely subject to plate suction from adjacent active, eastward-dipping subduction zones (Baes and Sobolev, 2017), as well as the East African margin (Gerya, 2011) thermally weakened by the African superplume (Mulibo and Nyblade, 2013;Koptev et al, 2015Koptev et al, , 2018). However, despite numerical (Nikolaeva et al, 2010;Candioti et al, 2022) and laboratory (Faccenna et al, 1999;Auzemery et al, 2021) model inferences, no irrefutable natural example of initiated selfsustained subduction at a passive margin has yet been documented. Subduction zone transference is a composite dynamic process that invokes both the termination of subduction by terrane collision/accretion and the onset of subduction on the backside of the colliding block (Figure 1F).…”

Section: Passive Margin Collapse and Subduction Transference: Traditi...mentioning

confidence: 99%

“…For example, oceanic transform faults that have been considered as potential sites for purely spontaneous, gravity-driven collapse (Karig, 1982;Matsumoto and Tomoda, 1983;Dymkova and Gerya, 2013;Maunder et al, 2020) can hardly evolve into a subduction zone without either a horizontal or vertical external forcing (Leng et al, 2012;Arcay et al, 2020). Collapse of passive continental margins, another traditional example of the spontaneous mechanism (Vlaar and Wortel, 1976;Cloetingh et al, 1982;Nikolaeva et al, 2010), may also require significant additional forces (Auzemery et al, 2021;Candioti et al, 2022) originating from topographic gradients (Marques et al, 2013) and/or mantle suction induced by adjacent subduction-related flow (Baes and Sobolev, 2017). In this regard, recent systematic reviews of well-documented subduction initiations in the Late Mesozoic and Cenozoic fundamentally question the feasibility of spontaneous mechanisms, suggesting that horizontally forced scenarios predominate (Crameri et al, 2020;Lallemand and Arcay, 2021).…”

Section: Introductionmentioning

confidence: 99%

Ocean-continent subduction cannot be initiated without preceding intra-oceanic subduction!

et al. 2022

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The formation of new subduction zones is a key element of plate tectonics and the Wilson cycle, and many different controlling mechanisms have been proposed to initiate subduction. Here, we provide a brief overview of the known scenarios of subduction initiation in intra-oceanic and ocean-continent tectonic settings. Intra-oceanic subduction is most commonly associated with mechanical heterogeneities within the oceanic lithosphere, such as pre-existing fracture zones, spreading ridges, and transform faults. Numerous and well-recognized examples of new active subduction zones formed in intra-oceanic environments during the Cenozoic, suggesting that the initiation of ocean-ocean subduction must be a routine process that occurs “easily and frequently” in the mode of plate tectonics currently operating on Earth. On the contrary, the most traditional mechanisms for the establishment of classic self-sustaining ocean-continent subduction—passive margin collapse and subduction transference—are surprisingly rare in observations and difficult to reproduce in numerical models. Two alternative scenarios—polarity reversal and lateral propagation-induced subduction initiation—are in contrast much better documented in nature and experimentally. However, switching of subduction polarity due to arc-continent collision and lateral transmission of subducting plate boundaries are both inextricably linked to pre-existing intra-oceanic convergence. We, therefore, conclude that the onset of classic ocean-continent subduction zones is possible only through the transition from a former intra-oceanic subduction system. This transition is likely facilitated by the ductile damage accumulation and stress concentration across the aging continental margin. From this perspective, the future closure of the Atlantic Ocean can be viewed as an archetypal example of the role of transitional process between intra-oceanic subduction (Lesser Antilles) and the development of a new subduction zone at a passive continental margin (eastern North America).

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Passive margin inversion controlled by stability of the mantle lithosphere

Cited by 15 publications

References 138 publications

Kinematic Boundary Conditions Favouring Subduction Initiation at Passive Margins Over Subduction at Mid-oceanic Ridges

Kinematic Boundary Conditions Favouring Subduction Initiation at Passive Margins Over Subduction at Mid-oceanic Ridges

A submarine morphotectonic analysis combining GIS-based methods and virtual reality: Case study of the low-rate active thrust faulting off Boumerdès (Algeria)

Ocean-continent subduction cannot be initiated without preceding intra-oceanic subduction!

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