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...

Lavas from Afanasy-Nikitin Rise, possibly the Late Cretaceous product of the Crozet hotspot, cover a wide range of isotopic compositions that includes the lowest (Pb/Pb)t (to 16.77) and «Nd(t) (to 28) values yet found among oceanic islands or spreading centers worldwide, as well as high (Sr/Sr)t (to 0.7066). In contrast, young basalts from the Crozet Archipelago exhibit a narrow range of variat...

Noble gas concentrations and isotopic compositions have been measured in eight samples of pillow basalt glasses collected from seven different localities along 250 km of the Mariana Trough spreading and rifting axis. The samples have uniform and mid-ocean ridge basalt (MORB)-like He/He values of 9±12 ́ 10 (6.4±8.6 times atmospheric) despite large variations in He. Concentrations of the noble ga...

Late Paleozoic to early Mesozoic subduction complexes formed during the evolution of southwestern Gondwana and extensively crop out along Chilean continental margin. Recent findings in northern Patagonia (40°–43°S) revealed that accretionary processes were active since Devonian when enhanced lithosphere stretching forearc led formation Chaitenia island arc. The extension crust consecutively dev...

The Fe isotope systematics of subducted lithologies are crucial for the understanding redox-dependent mass transfer in subducting slabs, with consequences compositions arc magmas and deep mantle. We investigated eclogites, metagabbros, paragneisses from Variscan Münchberg Massif to unravel whether their dominated by igneous/sedimentary protolith signature, low-temperature seawater alteration, o...

The study of ultramafic rocks in Western Yunnan is great significance for an understanding the tectonic evolution Neo-Tethys Ocean. zircon U–Pb data indicated that Santaishan serpentinized pyroxene peridotite (SSPP) was formed 186–190 Ma, and Yingjiang hornblende pyroxenite (YHP) 182–183 Ma. content MgO SSPP relatively high, but SiO2, Al2O3, CaO TiO2 ΣREE are low, while YHP has opposite charact...

Abstract Although high-Mg andesites (HMA) have attracted increasing attention due to their unique geochemical composition and important geological significance, there is no consensus on petrogenesis. The present study indicates that the subducting terrigenous sediment-derived hydrous melts were incorporated into mantle source of Paleozoic HMA in northwestern Tianshan, western China. These are c...

This study presents a new geochemical, petrological, and geochronological U–Pb dataset from Ediacaran metabasites of the Canigó Cap de Creus massifs, Eastern Pyrenees. The rocks are composed calcic amphibole + plagioclase chlorite epidote ± quartz plus titanite apatite ilmenite biotite rutile as accessory phases show relict igneous textures. Peak pressure-temperature determinations share common...

This study investigates petrology and major, minor, and rare earth elements ‎geochemistry of ‎East Iranian Eocene–Oligocene volcanic rocks in Sistan suture ‎zone, to examine their ‎petrogenesis and magma evolution. The volcanic rocks include andesite, trachy-andesite, dacite ‎and rhyolite. ‎These calc-alkaline rocks of high-K series are enriched in Large ‎Ion Lithophile ‎Elements of Rb and Ba a...