Oxygen isotope ratios of olivine in 23 tholeiites from the Hawaii Scientific Drilling Project (HSDP) core (15 from Mauna Kea, 8 from Mauna Loa) and three samples of outcropping subaerial or dredged submarine Mauna Kea lavas have been measured by laser fluorination. The ~18o values are 4.6-5.4 %o, confirming previous observations that some Hawaiian lavas are derived from sources with ~18o values...

The detection of excess 142Nd caused by the decay of 103Ma half-life 146Sm in all terrestrial rocks compared with chondrites shows that the chondrite analogue compositional model cannot be strictly correct, at least for the accessible portion of the Earth. Both the continental crust (CC) and the mantle source of mid-ocean ridge basalts (MORB) originate from the material characterized by superch...

the halak abad prospect occurs in the northeastern part of central iran zone (sabzevar structural zone). in this investigation, geochemical evolution, age and source of part of northeastern iran magmatic arc (intrusive bodies) in halak abad area in the khorasan razavi province has been studied. the exposed rocks consist of volcanic rocks with andesite and dacite nature, limestone, plutonic rock...

The Bahla massif exposes the lower crustal section of Oman ophiolite located close to thrust front Semail nappe. It is affected by intense faulting previously attributed tectonic events that dismembered a classical ophiolitic sequence during or after obduction. Here we show most this complexity primary, inherited from syn-accretion tectonics. exposed in 15 8 km enclave surrounded mantle peridot...

• Record of adakitic high-Mg# magmatism along Hunter Ridge and Kadavu Island. records limited contribution from subducted sediments. Sr-Nd-Pb arc rocks record the melting subducting South Fiji MORB crust. This slab-melt component is also recorded in common (non-adakitic) rocks. Dehydration serpentinites leads to flux-melting unaltered MORB. The mostly submarine Ridge, located SW Pacific a ∼12 M...

Lithium elemental and isotopic compositions of olivines in peridotite xenoliths from Hebi in the North China Craton provide direct evidence for the highly variable δ(7)Li in Archean lithospheric mantle. The δ(7)Li in the cores of olivines from the Hebi high-Mg# peridotites (Fo > 91) show extreme variation from -27 to +21, in marked deviation from the δ(7)Li range of fresh MORB (+1.6 to +5.6) al...

Abstract Brown amphibole is a minor but common mineral component in lower oceanic crust. It generally interpreted as products of migrating SiO2 and H2O-rich fluids or melts, which can be either residual melts from advanced magmatic differentiation Mid-Ocean Ridge Basalt (MORB), hydrothermal including seawater component. Within the crust exhumed at Atlantis Bank Oceanic Core Complex, along ultra...