Timing of Eocene compressional plate failure during subduction initiation, northern Zealandia, southwestern Pacific

Hypothesis for Cretaceous rifting of east Gondwana caused by subducted slab capture

In the process of subducted slab capture, a spreading ridge approaches subparallel to a subduction zone following the trailing edge of a downgoing plate. Eventually the downgoing plate is too young and small to subduct, and spreading stops. The spreading ridge stalls many tens of kilometres outboard of the subduction zone. The subducted plate welds to the outboard plate across the dormant sprea...

Mid-mantle seismic anisotropy beneath southwestern Pacific subduction systems and implications for mid-mantle deformation

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...

Ridge subduction sparked reorganization of the Pacific plate-mantle system 60–50 million years ago

A reorganization centered on the Pacific plate occurred ~53–47million years ago. A “top-down” plate tectonic mechanism, complete subduction of the Izanagi plate, as opposed to a “bottom-up”mantle flow mechanism, has been proposed as the main driver. Verification based on marine geophysical observations is impossible as most ocean crust recording this event has been subducted. Using a forward mo...

Motion on Upper-Plate Faults During Subduction Zone Earthquakes: Case of the Atacama Fault System, Northern Chile

Subduction initiation at relic arcs

Although plate tectonics is well established, how a new subduction zone initiates remains controversial. Based on plate reconstruction and recent ocean drilling within the Izu-Bonin-Mariana, we advance a new geodynamic model of subduction initiation (SI). We argue that the close juxtaposition of the nascent plate boundary with relic oceanic arcs is a key factor localizing initiation of this new...