Impact of tectonic rafts’ gravitational instability on fault reactivation and geometry

Folding and fracturing of rocks adjacent to salt diapirs

“…For example, in the Santos Basin, radial faults that extend beyond the limit of drape folding (Coleman et al, 2018) have two dominant trends that also exist in minibasins between the diapirs, and roof strata well above regional imply some contractional deformation. A similar situation occurs in the Espírito Santo Basin (Mattos and Alves, 2018;Maunde and Alves, 2020). Third, we find no field evidence, in the form of mesoscale structures or microscopic fabrics, of the shortening required if diapirs are expanding into the minibasins.…”

“…Radial extensional faults have been observed both over the crests of buried diapirs and around diapir flanks (Fig. 4d) (e.g., Hempel, 1967;Brinkmann and Lötgers, 1968;Davison et al, 2000a;Rowan et al, 2003;Stewart, 2006;Quintà et al, 2012;Carruthers et al, 2013;Salazar et al, 2014;Harding and Huuse, 2015;Coleman et al, 2018;Mattos and Alves, 2018;Maunde and Alves, 2020). Those above the diapirs have been attributed to doming and the consequent concentric tensile stress.…”

Shallow fault systems of thrust anticlines responding to changes in accretionary prism lithology (Nankai, SE Japan)

“…The measured throw values were plotted against depth to assess their nucleation points, and vertical growth styles, as well as gather information about the competence of sediments they had affected. Throw-depth (T-Z) profiles offer information on the rock competence, nucleation, growth, segmentation, and linkage of individual faults (e.g., Baudon and Cartwright, 2008;Maunde and Alves, 2020). Discrepancies in throw gradients commonly result from mechanical heterogeneities, fault reactivation and fault segmentation (e.g., Childs et al, 1996;Baudon and Cartwright, 2008;Laubach et al, 2009).…”

Segmented growth of reactivated major bounding faults and their control on basin structures: Insights from the Nanpu Sag, Bohai Bay Basin, eastern China

“…Cases of anticline formation in extensional settings have also been reported in places such as northern California (Kattenhorn et al., 2016) and the Gulf of Thailand (Morley, 2017), as well as analog extensional models. Anticlines in extensional regimes can be broadly divided into two types: (1) rollover anticlines, which develop to accommodate the space created by the differential dip‐slip components at different positions of the listric faults hanging wall (Maunde & Alves, 2020) and (2) transverse anticlines, which develop at the joints of fault segments due to small displacements (Kattenhorn et al., 2016). XF2 has both conditions, thereby promoting the formation of an anticline, including a “slope‐flat” geometry in profile view (Figure 5b) and segmented characteristics in map view (Figure 3b).…”