| Abstract: | Routine low-blank chemistry and 0.01-0.04% precision on the ratio 176Hf/177Hf allows study of Hf isotopic variations, generated by beta --decay of 176Lu, in volcanic rocks derived from the suboceanic mantle. Normalized to 176Hf/177Hf = 0.7325, 176Hf/177Hf ranges 0.2828-0.2835, based on 24 basalt samples. 176Hf/177Hf is positively correlated with 143Nd/144Nd, and negatively correlated with 87Sr/86Sr and 206Pb/204Pb. Along the Iceland-Reykjanes ridge traverse, 176Hf/177Hf increases southwards. The coherence of Hf, Nd and Sr isotopes in the oceanic mantle allows an approximate bulk Earth 176Hf/177Hf of 0.28295 to be inferred from the bulk Earth 143Nd/144Nd. This requires the bulk Earth Lu/Hf to be 0.25, similar to that of the Juvinas eucrite. 60% of the Hf isotopic variation in oceanic basalts occurs among mid-ocean ridge samples. Lu-Hf fractionation probably decouples from Sm-Nd and Rb-Sr fractionation in very depleted source regions, with high Lu/Hf, and consequent high 176Hf/177Hf ratios developing in mantle residual from partial melting. (Authors‘ abstract) -T.R. |
| Genre: | Article |
| ProdID: | 70012369 |
| Citation Author: | Patchett, P. J.; Tatsumoto, M. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 1080 |
| Citation Issue: | 12 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Geophysical Research Letters |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 4 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Hafnium isotope variations in oceanic basalts.; 1980; Article; Journal; Geophysical Research Letters; Patchett, P. J.; Tatsumoto, M. |
| Citation Start Page: | 1077 |
| Citation Volume: | 7 |
| Citation Year: | 1980 |
| Type: | citation/reference |
| Text: | Hafnium isotope variations in oceanic basalts.; 1980; Article; Journal; Geophysical Research Letters; Patchett, P. J.; Tatsumoto, M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 1980 00:00 -0600 |
| Publisher: | |
