Large igneous province subduction is a rare process on Earth. A modern example is the subduction of the oceanic Hikurangi Plateau beneath the southern Kermadec arc, offshore New Zealand. This segment of the arc has the largest total lava volume erupted and the highest volcano density of the entire Kermadec arc. Here we show that Kermadec arc lavas south of ~32°S have elevated Pb and Sr and low ...

The reduction of six wide-angle reflection profiles shot within the two fault blocks visited by Ocean Drilling Program (ODP) Leg 116 in combination with the ODP sonic logs has produced a velocity-depth structure for this area. The sediment velocity increases from 1.6-1.7 km/s in the near surface to 3.4-3.5 km/s immediately above basement with a velocity gradient of 0.75/s. A depth converted sei...

[1] The CHAMP satellite continues to provide highly accurate magnetic field measurements from decreasing orbital altitudes (<350 km) at solar minimum conditions. Using the latest 4 years (2004–2007) of readings from the CHAMP fluxgate magnetometer, including an improved scalar data product, we have estimated the lithospheric magnetic field to spherical harmonic degree 120, corresponding to 333 ...

The impact of mechanical layering and the strength of the Indian lower crust on the dynamics of the modern India-Asia collisional system are studied using 3-D thermomechanical modeling. The model includes an Indian oceanic domain, Indian continental domain, and an Asian continental domain. Each domain consists of four layers: upper/lower crust, and upper/lower lithospheric mantle. The Tarim and...

■ Abstract The Cordilleran orogen of western North America is a segment of the Circum-Pacific orogenic belt where subduction of oceanic lithosphere has been underway along a great circle of the globe since breakup of the supercontinent Pangea began in Triassic time. Early stages of Cordilleran evolution involved Neoproterozoic rifting of the supercontinent Rodinia to trigger miogeoclinal sedime...

Part 1: The Earth and its Lithosphere Chemical composition and structure of the Earth. . . . . . . . . . . . . . . . . . . . . . . . . 3 The structure of the Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Primordial chemistry: Origin of the elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Formation and evolution of the earth. . . ...

At subduction zones, the deep seismogenic transition from a frictionally locked to steady sliding interface is thought to primarily reflect changes in rheology and fluid pressure and is generally located offshore. The development of fluid pressures within a seismic low-velocity layer (LVL) remains poorly constrained due to the scarcity of dense, continuous onshore-offshore broadband seismic arr...

[1] New GPS measurements demonstrate tectonic segmentation of the South Shetland Islands platform, regarded as a microplate separating the Antarctic Peninsula from the oceanic portion of the Antarctic plate. King George, Greenwich, and Livingston islands on the central and largest segment are separating from the Antarctic Peninsula at 7–9 mm/a, moving NNW, roughly perpendicular to the continent...