Sedimentary loading, lithospheric flexure, and subduction initiation at passive margins

Rapid conversion of an oceanic spreading center to a subduction zone inferred from high-precision geochronology

“…These studies have demonstrated the need for a weak zone in the lithosphere to facilitate subduction. Based on this, subduction has been proposed to initiate in a variety of settings such as transform faults or fracture zones (10), passive continental margins (6,11), oceanic detachment faults (12), and oceanic spreading centers (13). Spreading centers have been the least favored, however, because the lithosphere there is positively buoyant.…”

Formation of plate boundaries: The role of mantle volatilization

“…In fact, there is no example of SNSZ at passive margins during the Cenozoic (Stern, 2004). Therefore, collapse under a tensional or strike-slip tectonic setting has been invoked (Turcotte et al, 1977;Erickson, 1993;Kemp and Stevenson, 1996). Accordingly, numerical simulations show that lithosphere in contact with another one along a transform fault/ fracture zone could be unstable if there is enough difference in age (e.g.…”

Models for the evolution of passive margins

“…Although the mechanisms by which this transition takes place are unclear (e.g., Erickson, 1993), there is evidence from backstripping of biostratigraphic data that foreland basins are underlain by stretched crust (e.g., the western deep Gulf of Mexico basin which overlies the western Gulf Coast margin (Feng et al, 1994), the Papuan basin which overlies the Northwest Australia margin (Haddad and Watts, 1999) and the west Taiwan basin which overlies the South China Sea margin (Lin and Watts, 2002)). Figure 3.1 shows an example of one such backstrip curve from the Colville Trough (north slope, Alaska), a flexural foreland basin that formed as a result of thrust/fold loading in the Brooks Ranges.…”