Low-temperature thermochronometry reveals regional Late Cenozoic denudation in Fiordland, New Zealand, consistent with geodynamic models showing uplift of the overriding plate during incipient subduction. The data show a northward progression of exhumation in response to northward migration of the initiation of subduction. The locus of most recent uplift coincides with a large positive Bouguer ...

The Kab Amiri area in the Central Eastern Desert (CED) of Egypt comprises ophiolitic rocks, island arc metasediments, and granitic rocks. This study deals with petrography geochemistry rocks to understand their petrogenesis geodynamic evolution CED belt. ophiolite is dismembered, comprising serpentinites metabasalt (spilite). Serpentinites have low contents Al2O3 (1.14 wt%) CaO (0.65 wt%), sugg...

We show that a new subduction zone can initiate at a preexisting dipping fault zone with reasonable plate forces, consistent with what is observed in the western Pacific. The dynamics of subduction initiation within a viscoelastic medium has been systematically explored with the finite element method. We investigate the compression of oceanic lithosphere with hoth force and velocity boundary co...

Observations of seismic anisotropy can offer relatively direct constraints on patterns of mantle deformation, but most studies have focused on the upper mantle. While much of the lower mantle is thought to be isotropic, several recent studies have found evidence for anisotropy in the transition zone and uppermost lower mantle (the mid-mantle), particularly in the vicinity of subducting slabs. H...

Sandbox modeling is used to study the deformation of accretionary wedges caused by the subduction of oceanic ridges. The first experiment incorporates a massive ridge within a sand wedge. The wedge thickens and shortens when the forward propagation f the basal decollement ceases. The wedge thickening results in taper change, reactivation of preexisting thrusts, and retreat of the frontal part o...

Subduction zones generate voluminous magma and mediate global element cycling. Fluids are essential to this activity, yet their behavior is perhaps the most poorly understood aspect of the subduction process. Though many volatile components are subducted, H2O is the most abundant, is preferentially fractionated into the fluid phase, and, among terrestrial volatiles, is by far the most effective...

Central Mexico is the site of an enigmatic zone of flat subduction. The general geometry of the subducting slab has been known for some time and is characterized by a horizontal zone bounded on either side by two moderately dipping sections. We systematically evaluate proposed hypotheses for shallow subduction in Mexico based on the spatial and temporal evidence, and we find no simple or obviou...