Recycled oceanic crust is believed to have played an important role in the formation of continental flood basalts, whereas involvement large amounts CO2 derived from recycled marine carbonate their mantle sources highly debated. Zn isotopes great potential trace due distinctly different δ66Zn values between carbonates and mantle. Representative basalt samples Keping (Group1) Yingmai Shengli (Gr...

Oceanic island basalts have a large range in dO values (4·5– INTRODUCTION 7·5‰) compared with the assumed primordial mantle values A 1996 conference on ‘shallow level processes in ocean (5·5–6·0‰) and with mid-ocean ridge basalts (5·7 ± 0·2‰). island magmatism’ drew attention to the controversy that Some Hawaiian tholeiitic basalts have low O values (4·6–5·2‰), is developing on the possible ext...

Late Miocene (7–9 Ma) basaltic rocks from the Monbetsu-Kamishihoro graben in northeast Hokkaido have chemical affinities to certain back-arc basin basalts (referred to herein as Hokkaido BABB). Pb-, Ndand Sr-isotopic compositions of the Hokkaido BABB and arc-type volcanic rocks (11–13 Ma and 4–4.5 Ma) from the nearby region indicate mixing between the depleted mantle and an EM II-like enriched ...

a r t i c l e i n f o Keywords: Large Igneous Province atmospheric carbon dioxide Triassic–Jurassic CO 2 chemical weathering Recent evidence from the ~201.5 Ma Central Atlantic Magmatic Province (CAMP) in the Newark rift basin demonstrates that this Large Igneous Province produced a transient doubling of atmospheric pCO 2 , followed by a falloff to pre-eruptive concentrations over ~300 kyr. Thi...

Earth analogues for Martian canyons. Steep-walled, amphitheater canyons on Mars have been invoked as evidence for underground water flow because of their similarities to seepage or sapping valleys/canyons on Earth. However, seepage canyon formation on Earth is speculative, particularly in basalt terrains (Lamb et al., 2006), and therefore analogies to Mars may be inappropriate. One of these Ear...

We report new high-precision laser fluorination three-isotope oxygen data for lunar materials. Terrestrial silicates with a range of δO values (−0.5 to 22.9‰) were analyzed to independently determine the slope of the terrestrial fractionation line (TFL; λ=0.5259±0.0008; 95% confidence level). This new TFL determination allows direct comparison of lunar oxygen isotope systematics with those of E...