Plate rupture by hydraulic fracture resulting in overthrusting

Abstract

Lithospheric plates, bending into subduction zones, may become ruptured by hydraulic fracturing initiated by the injection of mobilized sediments. Thick, poorly indurated, water-laden sediments of the proximal continental rise are the most obvious potential source for the large volume of material required for this process. Rupture of the descending plate may result in the subducted oceanic part of the lithosphere becoming detached and sinking independently, while the more buoyant continental part rises by isostatic rebound. We show here that applying this model to eastern Indonesia provides an explanation for the Banda Arc geometry, the apparent absence of a normal forearc and for the position of the thrust sheets relative to the Benioff zone¹. We also report that it can account for the short phase of deformation of the Australian continental margin preceding its uplift of 3 km (ref. 1).