TY - JOUR
T1 - Sr Isotopic Variations along the Juan de Fuca Ridge
AU - Eaby, Jacqueline
AU - Clague, David A.
AU - Delaney, John R.
AU - Dixon, Jacqueline E.
PY - 1984/9/1
Y1 - 1984/9/1
N2 - Sr isotopic ratios of 39 glass and microcrystalline basalt samples along the Juan de Fuca Ridge and 1 glass sample from Brown Bear Seamount are at the lower end of the range for normal mid‐oceanic ridge basalt (MORB); the average 87 Sr/ 86 Sr ratio is 0.70249±0.00014 (2‐σ). Although subtle variations exist along strike of the ridge, the Sr isotope data do not show systematic variation relative to the proposed Cobb Hotspot. The isotopic data are inconsistent with an enriched mantle‐plume origin for the Cobb‐Eickelberg Seamount chain, as has been proposed for Iceland, the Azores, and the Galapagos spreading center. Sr isotopic ratios of samples collected north and south of the Cobb offset are identical, although minor element ratios indicate that these regions have chemically distinct mantle sources. These distinct mantle sources may not have been separated long enough to develop isotopic differences.
AB - Sr isotopic ratios of 39 glass and microcrystalline basalt samples along the Juan de Fuca Ridge and 1 glass sample from Brown Bear Seamount are at the lower end of the range for normal mid‐oceanic ridge basalt (MORB); the average 87 Sr/ 86 Sr ratio is 0.70249±0.00014 (2‐σ). Although subtle variations exist along strike of the ridge, the Sr isotope data do not show systematic variation relative to the proposed Cobb Hotspot. The isotopic data are inconsistent with an enriched mantle‐plume origin for the Cobb‐Eickelberg Seamount chain, as has been proposed for Iceland, the Azores, and the Galapagos spreading center. Sr isotopic ratios of samples collected north and south of the Cobb offset are identical, although minor element ratios indicate that these regions have chemically distinct mantle sources. These distinct mantle sources may not have been separated long enough to develop isotopic differences.
UR - https://digitalcommons.usf.edu/msc_facpub/1321
U2 - 10.1029/JB089iB09p07883
DO - 10.1029/JB089iB09p07883
M3 - Article
VL - 89
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
ER -