Mechanisms of magma generation beneath hawaii and mid-ocean ridges: uranium/thorium and samarium/neodymium isotopic evidence.
Measurements of uranium/thorium and samarium/neodymium isotopes and concentrations in a suite of Hawaiian basalts show that uranium/thorium fractionation varies systematically with samarium/neodymium fractionation and major-element composition; these correlations can be understood in terms of simple batch melting models with a garnet-bearing peridotite magma source and melt fractions of 0.25 to 6.5 percent. Midocean ridge basalts shows a systematic but much different relation between uranium/thorium fractionation and samarium/neodymium fractionation, which, although broadly consistent with melting of a garnet-bearing peridotite source, requires a more complex melting model.
Sims
K W
KW
Depaolo
D J
DJ
Murrell
M T
MT
Baldridge
W S
WS
Goldstein
S J
SJ
Clague
D A
DA