Frontal accretion and thrust wedge evolution under very oblique plate convergence: Fiordland Basin, New Zealand

Abstract

Basin Research, v. 14, n. 4, p. 439-466, 2002. http://dx.doi.org/10.1046/j.1365-2117.2002.00178.xInternational audienc

Strike-slip structure and sedimentary basins of the southern Alpine Fault, Fiordland, New Zealand

“…The surface trace of the interplate thrust is exposed in the Fiordland and Milford Basins some 25-30 km northwest of the Alpine Fault Barnes et al, 2002). Lebrun et al (2000) interpreted two major submarine traces of the Alpine Fault southwest of Milford Sound (Fig.…”

“…2), and mapped at a scale of 1: 200,000. The majority of the seismic profi les were collected by the National Institute of Water and Atmospheric Research (NIWA) on R/V Tangaroa in 1998 (Barnes et al, 2001(Barnes et al, , 2002. These low-fold profi les typically image the subsurface sedimentary section in the vicinity of the Alpine Fault to a depth of 1.0-1.5 s (two-way travel time).…”

Postglacial (after 20 ka) dextral slip rate of the offshore Alpine fault, New Zealand

“…The Fiordland region is thus an excellent example of strain being highly partitioned within an obliquely convergent plate boundary zone. Thrust faulting west of the Alpine fault appears to accommodate a substantial percentage of the predicted 15 mm/yr of shortening across the plate boundary (Barnes et al, 2002).…”

“…The southern Alpine fault is above the Fiordland subduction zone, landward of a thrust wedge (Barnes et al, 2002). The fault is segmented, and is associated with releasing bends and pull-apart basins (Barnes et al, 2001(Barnes et al, , 2005.…”

Uplift rate and landscape development in southwest Fiordland, New Zealand, determined using 10Be and 26Al exposure dating of marine terraces

“…The Australian plate is being obliquely subducted beneath Fiordland and is imaged as a steeply dipping, seismically active, high seismic velocity zone to ϳ150 km depth (Davey and Smith, 1983;Eberhart-Phillips and Reyners, 2001). Plate motion of approximately 36 mm/yr is partitioned between subduction and trench-slope convergence (Barnes et al, 2002), Alpine Fault dextral motion of ϳ26 mm/yr (Sutherland, 1994;Sutherland and Norris, 1995;Barnes, 2001), and distributed convergence across the 300 km width of South Island (Norris, 1979;Walcott, 1998). Estimates of when the Australian plate started to be subducted vary from 7 to 14 Myr (Davey and Smith, 1983;Walcott, 1998;House et al, 2002) and regional geology shows that the Fiordland region has experienced a progressively increasing convergence rate since 20 -30 Myr (Turnbull and Uruski, 1993).…”