We obtained a 3D image of crust and mantle seismic velocity gradients beneath the state Alaska using common-conversion point (CCP) stacking S-to-p converted body waves recorded by hundreds stations from NSF EarthScope Transportable Array other portable arrays permanent networks. Moho depths delineate thick underthrust Yakutat terrane crustal root Brooks Range. The North American lithosphere is ...

Rocks metamorphosed under high-pressure (HP) and ultra high-pressure (UHP) conditions in subduction zones come back to the surface relatively soon after their burial and at rates comparable to plate boundary velocities. In the Mediterranean realm, their occurrence in several belts related to a single subduction event shows that the burial-exhumation cycle is a recurrent transient process. Using...

The existence of partial melt is frequently invoked to explain geophysical anomalies such as low seismic wave velocity and high electrical conductivity. I review various experimental and theoretical studies to evaluate the plausibility of this explanation. In order for a partial melt model to work, not only the presence of melt, but also the presence of appropriate amount of melt needs to be ex...

Experimental approaches attempt to determine the routes by which crustal carbonatite magmas can be derived from C02-bearing peridotite at high pressures. The intimate association of kimberlite and carbonatite on a small scale il· lustrates links in the processes. Carbonation of peridotite by C02 can cause the generation of near-solidus carbonatitic liquid from mantle peridotite at depths greate...

Abstract We present mineralogical and geochemical compositions of mantle xenoliths from two Cenozoic basalt localities the northeastern North China Craton. These include lherzolite, harzburgite, websterite. They are generally fertile in major elements different typical cratonic lithosphere, which is consistent with previous hypotheses regarding craton destruction. The ratios 87Sr/86Sr (La/Yb)N ...