Helium isotopes are a robust geochemical tracer of a primordial mantle component in hot spot volcanism. The high ³He/⁴He (up to 35 RA, where RA is the atmospheric ³He/⁴He ratio of 1.39 X 10¯⁶) of some Hawaiian Island volcanism is perhaps the classic example. New results for picrites and basalts...
We report ³He/⁴He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81°E and 101°E ³He/⁴He varies from 7.5 to 10.2 R[subscript A], encompassing more than half the
MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the...
We report ³He/⁴He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81°E and 101°E ³He/⁴He varies from 7.5 to 10.2 R[subscript A], encompassing more than half the
MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the...
Full Text:
/4He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81�E
The Cobb Seamount Chain in the northeast Pacific basin records the composition of the Cobb hot spot for the past 33 Myr, as the migrating Juan de Fuca Ridge approached and ultimately overran it ca. 0.5 Myr ago. In this first comprehensive geochemical study of the Cobb chain, major and...
We report ³He/⁴He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81°E and 101°E ³He/⁴He varies from 7.5 to 10.2 R[subscript A], encompassing more than half the
MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the...
Hot spot–mid-ocean ridge interactions cause many of the largest structural and chemical anomalies in Earth’s ocean basins. Correlated geophysical and geochemical anomalies are widely explained by mantle plumes that deliver hot and compositionally distinct material toward and along mid-ocean ridges. Compositional anomalies are seen in trace element and isotope ratios,...
