thumbnail

Pb, Sr, and Nd isotopes in seamount basalts from the Juan de Fuca Ridge and Kodiak-Bowie seamount chain, northeast Pacific

Journal of Geophysical Research

By:
,

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time

Abstract

Pb, Sr, and Nd isotopic ratios and their parent/daughter element concentrations for 28 basalts from 10 hotspot and nonhotspot seamounts are reported. Nd and Sr isotopic compositions (143Nd/144Nd = 0.51325-0.51304; 87Sr/86Sr = 0.70237-0.70275) plot in the envelope for Juan de Fuca-Gorda ridge basalts with tholeiitic basalts showing more depleted sources and a better negative correlation than transitional to alkalic basalts. Pb isotopic ratios in tholeiitic and alkalic basalts overlap (206Pb/204Pb = 18.29-19.44) and display a trend toward more radiogenic Pb in alkalic basalts. The isotopic data for hotspot and nonhotspot basalts are indistinguishable and correlate broadly with rock composition, implying that they are controlled by partial melting. The isotopic variation in the seamount basalts is about 60% (Nd-Sr) to 100% (Pb) of that in East Pacific Rise basalts and is interpreted as a lower limit for the magnitude of mantle heterogeneity in the northeast Pacific. The data indicate absence of a chemically distinct plume component in the linear seamount chains and strongly suggest an origin from mid-ocean ridge basalt-like east Pacific mantle. -Authors

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Pb, Sr, and Nd isotopes in seamount basalts from the Juan de Fuca Ridge and Kodiak-Bowie seamount chain, northeast Pacific
Series title:
Journal of Geophysical Research
Volume
94
Issue:
B12
Year Published:
1989
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article