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A search for 142 Nd evidence of primordial mantle heterogeneities in plume basalts
Author(s) -
Boyet Maud,
Garcia Michael O.,
Pik Raphaël,
Albarède Francis
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl021873
Subject(s) - basalt , mantle (geology) , mantle plume , geology , geochemistry , plume , solid earth , geophysics , physics , tectonics , paleontology , thermodynamics , lithosphere
In order to assess whether material differentiated shortly after terrestrial accretion is still present in the deep mantle, we investigated hot spot basalts for 142 Nd/ 144 Nd anomalies that could attest for the presence of live 146 Sm (T 1/2 = 103 My) at the time the mantle source of these basalts formed. We analyzed high 3 He/ 4 He basalts from Loihi and Ethiopia and normal 3 He/ 4 He basalts from Iceland. Although the 143 Nd/ 144 Nd ratios of these basalts reflect a source with long‐term LREE (light rare earth elements) depletion, no resolvable 142 Nd anomalies were detected. Taking the analytical uncertainties (10–20 ppm) into account, however, the present results do not rule out the possibility that a large proportion of material fractionated very early in the Earth's history may still be hidden in the deep mantle.