Tracing the origin of continental HIMU-like intraplate volcanism using magnesium isotope systematics

Hafnium isotopic variations in East Atlantic intraplate volcanism

The broad belt of intraplate volcanism in the East Atlantic between 25 and 37 N is proposed to have formed by two adjacent hotspot tracks (the Madeira and Canary tracks) that possess systematically different isotopic signatures reflecting different mantle source compositions. To test this model, Hf isotope ratios from volcanic rocks from all individual islands and all major seamounts are presen...

Kalkkop Crater, Cape Province, South Africa: Confirmation of impact origin using osmium isotope systematics

The Kalkkop structure, a circular depression with a diameter of 640 m, is situated in the Eastern Cape Province, South Africa. In 1992, a bore hole was drilled in the center of the crater to a depth of 15 1.8 m. To assess a possible impact origin of this structure, the abundances and isotopic ratios of osmium and rhenium were measured in breccias and in sandstones and shales derived from the ba...

Sizes and Ages of Seamounts Using Remote Sensing: Implications for Intraplate Volcanism

Satellite altimetry is used to identify and characterize Pacific intraplate seamounts. The gravimetric amplitudes of seamounts appear to be related to the age difference between seafloor and seamounts; by inverting this relationship pseudo ages can be obtained for undated seamounts. These pseudo ages imply that excursions in seamount volcanism generally correlate with times of formation of larg...

Osmium isotope systematics of ureilites

The Os/Os for 22 ureilite whole rock samples, including monomict, augite-bearing, and polymict lithologies, were examined in order to constrain the provenance and subsequent magmatic processing of the ureilite parent body (or bodies). The Re/Os ratios of most ureilites show evidence for a recent disturbance, probably related to Re mobility during weathering, and no meaningful chronological info...

Temporal and geochemical evolution of the Cenozoic intraplate volcanism of Zealandia