[1] Using three-dimensional (3-D) instantaneous dynamic models of the Central Aleutian subduction zone, we show that a low viscosity, low density (dr = 10 kg/m) region in the wedge is needed to match observations of topography, the geoid and the stress-state in the slab and overriding plate. Previous models of the Tonga-Kermadec subduction zone also require a low viscosity, low density (dr = 20...

A model for the tectonic evolution of the Eastern Mediterranean region from Mesozoic to Present is developed from geological, geophysical, and seismological data on and surrounding the island of Cyprus. This model emphasizes the role of major transform structures in accommodating horizontal plate motions, driven from the west by spreading along the Atlantic-Arctic mid-ocean-ridge system and fro...

New geochemical data for Pleistocene magmatic rocks from the Surigao peninsula, eastern Mindanao, the Philippines, demonstrate typical adakitic traits, including elevation of Sr /Y and depletion of the heavy rare earth elements. Sr / Sr and Nd / Nd ratios of the adakites do not support melting of the subducted Philippine Sea Plate but resemble Pliocene arc lavas generated in the same subduction...

The B and Pb isotope systems are widely applied tracers of recycling processes occurring during subduction. Studies examining these complementary systems as a pair enjoy considerable success, where B primarily records the thermal and fluid evolution of the subducting slab, whereas the tripartite Pb system constrains the source of subducted material returned to volcanic arcs. However, interpreta...

A viscous flow model of a subduction zone is used to calculate the near-trench deformation and topography of the overriding plate in response to tectonic and buoyancy forces. The tectonic force, which is associated with global plate motion, arises from subduction of a cold oceanic lithosphere that shears the overriding lithosphere along the contact between the two plates. The buoyancy force ari...

[1] We report on laboratory experiments examining the frictional and hydrologic properties of fault gouge and wall rock along a borehole transect that crosses a major out-of-sequence thrust splay fault within the Nankai accretionary complex. At 25 MPa effective normal stress, the fault zone material is frictionally weak (m 0.44) and exhibits low permeability after shearing (k < 5.5 10 20 m). Fa...