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| Hamelin, Cedric; Dosso, Laure; Hanan, Barry B.; Moreira, Manuel; Kositsky, Andrew P.; Thomas, Marion Y.. |
| Samples collected during the PACANTARCTIC 2 cruise fill a sampling gap from 53 degrees to 41 degrees S along the Pacific Antarctic Ridge (PAR). Analysis of Sr, Nd, Pb, Hf, and He isotope compositions of these new samples is shown together with published data from 66 degrees S to 53 degrees S and from the EPR. The recent advance in analytical mass spectrometry techniques generates a spectacular increase in the number of multidimensional isotopic data for oceanic basalts. Working with such multidimensional datasets generates a new approach for the data interpretation, preferably based on statistical analysis techniques. Principal Component Analysis (PCA) is a powerful mathematical tool to study this type of datasets. The purpose of PCA is to reduce the... |
| Tipo: Text |
Palavras-chave: Oceanic basalts; Pacific-Antarctic Ridge; Mantle heterogeneity; Principal Component Analysis; Sr Nd Pb Hf isotopes. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14197/11508.pdf |
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| Graham, David W.; Hanan, Barry B.; Hemond, Christophe; Blichert-toft, Janne; Albarede, Francis. |
| We report He-3/He-4 for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian Ridge (SEIR). Between 81 degrees E and 101 degrees E He-3/He-4 varies from 7.5 to 10.2 R-A, encompassing more than half the MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the full range occurs over similar to 10 km. Melting of lithologically heterogeneous mantle containing a few percent garnet pyroxenite or eclogite leads to lower He-3/He-4, while He-3/He-4 above similar to 9 R-A likely indicates melting of pyroxenite-free or eclogite-free mantle. Patterns in the length scales of variability represent a description of helium isotopic texture. We utilize four complementary methods of spectral analysis to evaluate this... |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00217/32839/31308.pdf |
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