An unbiased estimate of the arithmetic mean of the He/He ratio (R) of basalts from the global spreading ridge system is 9.14 + 3.59 Ra (n=503), where Ra is the atmospheric ratio and n is the number of data points. The + two standard deviation (2σ) range covers much of the oceanic island and continental flood basalt data that have been attributed to ‘plume’ or ‘lower mantle’ components. The high...

[1] Compositionally layered mantle models have often been invoked in order to explain the geochemistry observed at the Earth’s surface, specifically the discrepancy between ocean island basalt and mid-ocean ridge basalt compositions. One disadvantage of layered models is the reduction in cooling efficiency compared to whole-mantle convection as a direct result of the insulating nature of the th...

Magnetic stripes have long been assumed to be indicative of oceanic crust. However, continental crust heavily intruded by magma can also record magnetic stripes. We re-evaluate the nature Cuvier Abyssal Plain (CAP), offshore NW Australia, which hosts and has previously defined as show that chemical data from a basalt within CAP, described an enriched mid-ocean ridge basalt, could equally interp...

Mid-ocean ridge basalts (MORBs), produced at mid-ocean where the continents and subduction zones are distant, product of partial melting upper mantle their chemical composition can provide information about itself. The geochemical characteristics MORBs enable us to be more informed geological processes below ridge, assist in understanding heterogeneity geodynamic processes. In this paper, new d...

In this study, we present new data from microthermometry of fluid inclusions entrapped in hydrothermal veins along the Cocos Ridge from the IODP Expedition 344 Site U1414. The results of our study concern a primary task of IODP Expedition 344 to evaluate fluid/rock interaction linked with the tectonic evolution of the incoming Cocos Plate from the Early Miocene up to recent times. Aqueous, low ...

The upper mantle is a heterogeneous mixture of refractory and recycled crustal domains. portions, more fertile thus preferentially melted, dominate the composition basalts erupted on surface, whereas imprint melting counterparts difficult to discern from basalt chemistry. Contrasting radiogenic isotopic signatures mid-ocean ridge oceanic mantle, however, show that Hf isotope ratios may provide ...

Abstract The influence of Hainan mantle plume and subducting recycled oceanic crust beneath the spreading ridge South China Sea (SCS) have been widely proposed recently, but still controversial ambiguous. Here, we present seismic tomographic evidence, new major trace element, Pb isotopic compositions volcanic glasses from one International Ocean Drilling Program drill core (Site U1434) in SCS r...