The rate of subduction is larger than the convergence rate along W-directed subduction zones, whereas it is smaller along Eor NE-directed subduction zones. Along Wdirected slabs, the subduction rate is the convergence rate plus the slab retreat rate, which tends to equal the backarc extension rate. Along Eor NE-directed slabs, the subduction rate is decreased by the shortening in the upper plat...

Subduction of oceanic lithosphere occurs through two modes: subducting plate motion and trench migration. Using a global subduction zone data set and three-dimensional numerical subduction models, we show that slab width (W) controls these modes and the partitioning of subduction between them. Subducting plate velocity scales with W(2/3), whereas trench velocity scales with 1/W. These findings ...

[1] We give an explanation for the polarity, localization, shape, size, and initiation of subduction zones on Earth. By considering a soft, thin, curved lithospheric cap with either elastic or viscous rheology supported by a thick, nearly incompressible mantle, we find two different characteristic subduction geometries arise depending on boundary conditions: (1) plate boundaries where subductio...

Large subduction earthquakes on the Cascadia subduction zone pose a potential seismic hazard. Very young oceanic lithosphere (10 million years old) is being subducted beneath North America at a rate of approximately 4 centimeters per year. The Cascadia subduction zone shares many characteristics with subduction zones in southern Chile, southwestern Japan, and Colombia, where comparably young oc...

New geochronological and geochemical data on magmatic activity from the India-Asia collision zone enables recognition of a distinct magmatic flare-up event that we ascribe to slab breakoff. This tie-point in the collisional record can be used to back-date to the time of initial impingement of the Indian continent with the Asian margin. Continental arc magmatism in southern Tibet during 80-40 Ma...

in order to investigate deformation history preserved in the calcite twins in the hinterland of zagros, several samples have been collected from calcschists of the paleozoic sargaz complex in the faryab area, se iran. these samples are related to f1-recumbent folding and thrust shear zones. the twin width is about 1 and 3.8 µm (thin-twin regime); the twin strain amounts 5 and 10%; twin intensit...

Flat slab subduction has been attributed to various causes including mantle wedge dynamics, overriding by the upper plate, age of the subducting plate, and subduction of anomalously thick oceanic crust. One often favored explanation for flat slabs is the subduction of buoyant features on the oceanic plate in the form of an aseismic-ridge or oceanic plateau. We show through plate tectonic recons...

Abstraet The amount and type of organic matter present in an exceptionally complete upper Aptian to lower Cenomanian sequence of sediments from ODP site 763 on the Exmouth Plateau has been determined. Organic carbon concentrations average 0.2~o. Organic matter is marine in origin, and its production and preservation was low over the ca. 20-million-year interval recorded by this sequence. Becaus...

Developments in Earth system research have led to widespread interest multi-sphere interactions that may controlled bauxite formation. Although karst ores are abundant the Tethyan Metallogenic Domain (TMD), their genesis and distribution not yet fully understood. This study utilizes Random Forest (RF) model analyze geochemical data sets compiled from three provinces Tethys, including Mediterran...

The southwestern margin of the South China Craton preserves a Late Permian to Early Triassic sedimentary succession, provenance which helps constrain magmatic history and tectonic evolution Paleo-Tethyan Orogen. In this study, we present new detrital zircon U-Pb age, trace element, Hf isotope whole-rock geochemical composition analyses from Lower Qingtianbao Formation, distinguish clastic rocks...