Thermochronometric modelling predictions for model of inverted rifted margins (Model A; Fig. 1A). (A) Model thermochronological ages for the four low-temperature thermochronometers considered in this study. Low-temperature thermochronometers are apatite (U-Th)/He (AHe), apatite fission-track (AFT), zircon (U-Th)/He (ZHe) and zircon fission-track (ZFT) systems. Age predictions are plotted as boxplots against particle number and solid black squares represent model mean ages. PD: proximal domain, also margin; ND: necking domain; HE: hyperextended domain; EM: exhumed mantle domain. (B) Predicted chlorine content-dependent apatite and annealing model-dependent zircon mean track length data (MTL) plotted against model ages. Error bars shown for predicted MTL represent the standard deviation SD calculated by the software program QTQt (Gallagher, 2012; v5.7.1) and the colour scheme corresponds to margin domains as in (A) and Figure 1. Circles represent lower plate particles 1–8 and diamonds represent upper plate particles 9–14. For a given domain, colour shade allows differentiating particles from one another (for instance, regarding hyperextended domains, light purple corresponds to particle 6 while dark purple corresponds to particle 8). For each particle, four apatite age-MTL and three zircon age-MTL are predicted, depending on apatite chlorine content range and annealing model tested. In the AFT plot, point size increases with chlorine content. In the ZFT plot, small-sized points correspond to predictions obtained using the Yamada et al. (2007) short-time annealing model while medium-sized points correspond to predictions obtained using the Tagami et al. (1998) model. Large-sized points are indistinguishable as the Yamada et al. (2007) long-time annealing model yields the same results. They are represented in black. (C) Individual particles’ model time-temperature paths extracted from Model A (Figs. 1 and SI01). The colour scheme corresponds to margin domains as in (A) and Figure 1. Each plot represents one type of domain, irrespective of the plate (from bottom to top: exhumed mantle domain, hyperextended domains, necking domains, proximal domains) Ap.: apatite; Zr.: zircon; PAZ: fission-track partial annealing zone; PRZ: helium partial retention zone. Model data in (A) and (B) are generated for each particle through QTQt forward modelling of their individual time-temperature path in (C). Brown bars indicate the ages of extension and transition from extension to convergence in Model A (Fig. 1).

Thermochronometric modelling predictions for model of non-inverted, thermally-relaxed rifted margins (Model B; Fig. 2). (A) Model thermochronological ages for the four low-temperature thermochronometers considered in this study. Age patterns predicted for Model A (Fig. 3) are plotted in grey in (A) for comparison. (B) Predicted chlorine content-dependent apatite and annealing model-dependent zircon mean track length data (MTL) plotted against model ages. (C) Individual particles’ model time-temperature paths extracted from Model B (Fig. 2). Coloured dashed lines in (C) represent the portions of the particles’ time-temperature paths that have changed between Model A (inversion) and Model B (no inversion, pure postrift thermal relaxation). Brown bars indicate the ages of extension in Model B. See Figure 3 for details.

Thermochronometric modelling predictions for model of inverted rifted margins (Model A; Fig. 1A). (A) Model thermochronological ages for the four low-temperature thermochronometers considered in this study. Low-temperature thermochronometers are apatite (U-Th)/He (AHe), apatite fission-track (AFT), zircon (U-Th)/He (ZHe) and zircon fission-track (ZFT) systems. Age predictions are plotted as boxplots against particle number and solid black squares represent model mean ages. PD: proximal domain, also margin; ND: necking domain; HE: hyperextended domain; EM: exhumed mantle domain. (B) Predicted chlorine content-dependent apatite and annealing model-dependent zircon mean track length data (MTL) plotted against model ages. Error bars shown for predicted MTL represent the standard deviation SD calculated by the software program QTQt (Gallagher, 2012; v5.7.1) and the colour scheme corresponds to margin domains as in (A) and Figure 1. Circles represent lower plate particles 1–8 and diamonds represent upper plate particles 9–14. For a given domain, colour shade allows differentiating particles from one another (for instance, regarding hyperextended domains, light purple corresponds to particle 6 while dark purple corresponds to particle 8). For each particle, four apatite age-MTL and three zircon age-MTL are predicted, depending on apatite chlorine content range and annealing model tested. In the AFT plot, point size increases with chlorine content. In the ZFT plot, small-sized points correspond to predictions obtained using the Yamada et al. (2007) short-time annealing model while medium-sized points correspond to predictions obtained using the Tagami et al. (1998) model. Large-sized points are indistinguishable as the Yamada et al. (2007) long-time annealing model yields the same results. They are represented in black. (C) Individual particles’ model time-temperature paths extracted from Model A (Figs. 1 and SI01). The colour scheme corresponds to margin domains as in (A) and Figure 1. Each plot represents one type of domain, irrespective of the plate (from bottom to top: exhumed mantle domain, hyperextended domains, necking domains, proximal domains) Ap.: apatite; Zr.: zircon; PAZ: fission-track partial annealing zone; PRZ: helium partial retention zone. Model data in (A) and (B) are generated for each particle through QTQt forward modelling of their individual time-temperature path in (C). Brown bars indicate the ages of extension and transition from extension to convergence in Model A (Fig. 1).

Thermochronometric modelling predictions for model of non-inverted, thermally-relaxed rifted margins (Model B; Fig. 2). (A) Model thermochronological ages for the four low-temperature thermochronometers considered in this study. Age patterns predicted for Model A (Fig. 3) are plotted in grey in (A) for comparison. (B) Predicted chlorine content-dependent apatite and annealing model-dependent zircon mean track length data (MTL) plotted against model ages. (C) Individual particles’ model time-temperature paths extracted from Model B (Fig. 2). Coloured dashed lines in (C) represent the portions of the particles’ time-temperature paths that have changed between Model A (inversion) and Model B (no inversion, pure postrift thermal relaxation). Brown bars indicate the ages of extension in Model B. See Figure 3 for details.