Abstract The origin and evolution of subcontinental lithospheric mantle (SCLM) are important issues Earth’s chemical physical evolution. Here, we report detailed textural analyses on a xenolith suite from Befang (Oku Volcanic Group, Cameroon Line), which represents major tectono-magmatic structure the African plate. samples sourced spinel-facies dominated by lherzolites. Their texture is catacl...

This paper provides a summary of postcruise scientific results from Ocean Drilling Program (ODP) Leg 209 available to date, building upon shipboard observations and syntheses summarized in the Leg 209 Initial Results volume. During Leg 209, 19 holes were drilled at 8 sites along the Mid-Atlantic Ridge from 14°43′ to 15°44′N, mainly in residual mantle peridotite intruded by gabbroic rocks, in or...

An abundance of the trace elements has been determined in olivine Archean spinel-bearing phlogopite harzburgite enclave (sample UR17/2) from Bug granulite complex Ukrainian Shield by SIMS analysis. Major were analyzed SEM-EDS and EPMA The shows a homogeneous chemical composition: MgO — 45.20—45.64 wt.%, FeO 13.66—14.23 with Fo85—86 Fe/Mn ratio 68.3—68.6 which corresponds to 60—70 peridotites. N...

Titanium isotopes are a promising novel tracer for magmatic processes. The Ti isotope composition of the Earth's mantle is key using this on planetary scale, however, recent studies point to potential variations in rocks. This study presents stable data well-characterised peridotites from Horoman massif (Japan) as well primitive, orogenic (Variscan and Alpine belts) South African ultrapotassic ...

The occurrence of mantle-derived peridotite xenoliths in phonolitic melts is a rare phenomenon, and commonly ascribed to mantle origin the phonolite. alternative possibility, that are transported into evolving phonolite by mafic magmas, has received little attention. A unique tephriphonolite lava with groundmass composition, from active Cumbre Vieja volcano La Palma (Canary Islands), allows tes...

Many basalts from oceanic islands, ridges, and arcs show strong trace element evidence for melting at great depths, where garnet is a stable phase in mantle peridotites. If partial melts ascend to the surface by porous (intergranular) flow processes, the high-pressure garnet signature will be obliterated by diffusive reequilibration at shallower depths in the mantle. Spiegelman and Kenyon [Spie...

Volcanic rocks erupted among Pitcairn seamounts sample a mantle plume that exhibits an extreme Enriched Mantle-1 signature. The origin of this peculiar endmember remains contentious, and could involve the recycling marine sediments Archean or Proterozoic ages, delaminated units from lower continental crust, metasomatized peridotites lithospheric mantle. Here, we report sulfur multi-isotopic sig...

Abstract This study presents new secondary ion mass spectrometry (SIMS) reference materials (RMs) for measuring water contents in nominally anhydrous orthopyroxenes from upper mantle peridotites. The enstatitic spinel peridotite xenoliths have Mg#s between 0.83 and 0.86, Al 2 O 3 ranges 4.02 5.56 wt%, Cr 0.21 0.69 wt%. Based on Fourier-transform infrared spectroscopy (FTIR) characterizations, t...