Large-scale tectonic processes introduce a range of crustal lithologies into the Earth's mantle. These lithologies have been implicated as sources of compositional heterogeneity in mantle-derived magmas. The model being explored here assumes the presence of widely dispersed fragments of residual eclogite (derived from recycled oceanic crust), stretched and stirred by convection in the mantle. H...

New mineralogical and geochemical data from a suite of glass ± from the mantle (Deines & Gold, 1973; Nelson et al., 1988). However, controversy remains as to whether such apatite ± amphibole ± phlogopite ± carbonate-bearing spinel magmas represent (1) direct partial melts of carbonatewehrlite, lherzolite and harzburgite xenoliths from the Newer Volbearing mantle peridotite (i.e. primary carbona...

Excess volcanism and crustal swelling associated with hot spots are generally attributed to thermal plumes upwelling from the mantle. This concept has been tested in the portion of the Mid-Atlantic Ridge between 34 degrees and 45 degrees (Azores hot spot). Peridotite and basalt data indicate that the upper mantle in the hot spot has undergone a high degree of melting relative to the mantle else...

[1] Drilling during ODP Leg 209, dredging, and submersible dives have delineated an anomalous stretch of the Mid-Atlantic Ridge north and south of the 15 200N Fracture Zone. The seafloor here consists dominantly of mantle peridotite with gabbroic intrusions that in places is covered by a thin, discontinuous extrusive volcanic layer. Thick lithosphere (10–20 km) in this region inhibits magma fro...

In the recent years, the amounts of green house gases have dramatically increased. This situation led to changing in climate conditions. One of the effective ways to reduce these amounts in atmosphere is CO2 capturing from huge spreading sources and injection it into geological formations. Peridotite is a type of rock that reacts with CO2 at higher rate when compared to the other rocks. Since t...

Mantle-derived xenoliths brought to the Earth’s Surface by basalts are important windows to understand composition, evolution and processes of the lithospheric mantle. The lithosphere of the southeastern China is dominated by peridotite or lherzolite [1, 2]. The spinel peridotite xenoliths studied are from Fangshan basalt, eastern China, which are composed of olivine, clinopyroxene, orthopyroxe...

The deep carbon cycle plays an important role on the chemical differentiation and physical properties of the Earth's mantle. Especially in the asthenosphere, seismic low-velocity and high electrical conductivity due to carbon dioxide (CO2)-induced partial melting are expected but not directly observed. Here we discuss the experimental results relevant to the genesis of primitive CO2-rich alkali...

Abstract. Interaction between peridotite and pyroxenite-derived melts can significantly modify the mineralogy chemistry of upper mantle, enhancing its heterogeneity, by creating re-fertilized peridotites secondary-type pyroxenites. We experimentally investigated reaction a fertile lherzolite MgO-rich basaltic andesite produced partial melting an olivine-free pyroxenite at 2 GPa 1300–1450 ∘C. Th...

Pyroxenite-peridotite sequences from the External Liguride (EL) Jurassic ophiolites (Northern Apennines, Italy) consist of portions fertile MORB mantle that were modified by deep melt infiltration and melt-peridotite reaction. They represent an excellent natural example a MORB-like veined including unmodified peridotite, pyroxenite layers metasomatized peridotite. We carried out spatially contr...

The selected peridotite samples come from the Josephine ophiolite, emplaced 157 My ago and now part of the western Jurassic belt of the Klamath Mountains in Northern California and Southwest Oregon [1]. The ophiolite is partly dismembered but presents a complete ophiolitic section from mantle peridotites in the lower part (our samples) to pillow lavas at the top. The Josephine peridotite extend...