Seismic imaging of subducting continental lower crust beneath the Pamir

Continental crust beneath southeast Iceland.

The magmatic activity (0-16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from the nearby continental margins. A restricted area in southeast Icelan...

Seismic attenuation beneath Kanto, Japan: evidence for high attenuation in the serpentinized subducting mantle

The three-dimensional (3-D) P-wave attenuation (Qp ) structure beneath Kanto, Japan, is estimated by using a large number of waveform data. Corner frequencies of earthquakes are initially calculated from spectral ratios of S-coda waves, followed by an inversion to simultaneously determine attenuation terms and frequency-dependent site amplification factors. The attenuation terms are then invert...

Seismic Imaging of Microblocks and Weak Zones in the Crust Beneath the Southeastern Margin of the Tibetan Plateau

Seismic evidence for thermally-controlled dehydration reaction in subducting oceanic crust

[1] We perform travel-time tomography to estimate detailed seismic velocity structures in the crust of the Pacific slab from northeastern (NE) Japan to the Kanto district, Japan, and reveal that the depth extent of the low-velocity (hydrated) oceanic crust varies along the arc. The low-velocity oceanic crust is subducting to depths of 120–150 km beneath Kanto, which is 40–70 km deeper compared ...

The thermal structure of continental crust in active orogens: insight from Miocene eclogite and granulite xenoliths of the Pamir Mountains

Rare ultrahigh-temperature–(near)ultrahigh-pressure (UHT–near-UHP) crustal xenoliths erupted at 11 Ma in the Pamir Mountains, southeastern Tajikistan, preserve a compositional and thermal record at mantle depths of crustal material subducted beneath the largest collisional orogen on Earth. A combination of oxygen-isotope thermometry, major-element thermobarometry and pseudosection analysis reve...