Neodymium isotope

Davies GR, Halliday AN (1998) Development of the Long Valley rhyohtic magma system Strontium and neodymium isotope evidence from glasses and individual phenociysts. Geochim Cosmochim Acta 62 3561-3574... 

Sims KWW, DePaolo DJ, Murrell MT, Baldridge WS, Goldstein SJ, Clague DA (1995) Meehanisms of magma generation beneath Hawaii and mid-oeean ridges uranium/ thorium and samarium/ neodymium isotopic evidence. Seienee 267 508-512... 

MacPherson GJ, Huss GR, Davis AM (2003) Extinct Be in type A calcium-aluminum-rich inclusions from CV chondrites. Geochim Cosmochim Acta 67 3615-3179 Matthews GJ, Cowan JJ (1990) New insights into the astrophysical r-process. Nature 345 491-494 McCulloch MT, Wasserburg GJ (1978a) Barium and neodymium isotopic anomalies in the Allende meteorite. Astrophys J 220 L15-L19... 

De Laeter JR (2001) Applications of Inorganic Mass Spectrometry. Wiley, New York 496 p DePaolo DJ (1988) Neodymium isotope geochemistry an introduction. Spinger Verlag Berlin Heidelberg, Germany... 

Luais B, Telouk P, Albarede F (1997) Precise and accurate neodymium isotopic measurements by plasma-source mass spectrometry. Geochim Cosmochim Acta 61 4847-4854 Marechal C, Telouk P, Albarede F (1999) Precise analysis of copper and zinc isotopic compositions by plasma-source mass spectrometry. Chem Geol 156 251-273... 

Bau M, Dulski P (1996) Distribution of yttrium and rare-earth elements in the Penge and Kuruman iron-formations, Transvaal Supergroup, South Africa. Precam Res 79 37-55 Bau M, Hohndorf A, Dulski P, Beukes NJ (1997) Sources of rare-earth elements and iron in Paleoproterozoic iron-formations from the Transvaal Supergroup, South Africa evidence from neodymium isotopes. J Geol 105 121-129... 

Sims, K.W.W., DePaolo, D.J., Murrell, M.T., Baldridge, W.S., Goldstein, S.J. and Clague, D.A., 1995. Mechanisms of magma generation beneath Hawaii and mid-ocean ridges Uranium/thorium and samarium/neodymium isotopic evidence. Science, 267 508-512. 

Several samarium and neodymium isotopes are isobars (Table 4.2) and cannot be separated by mass spectrometry. Thus, samarium and neodymium must be completely separated by chemical procedures prior to measuring them in a mass spectrometer. The ion-exchange chemistry necessary to separate these elements is now well developed (see Appendix). Isotope measurements can be done either by TIMS or ICPMS (inductively... 

McCulloch, M. T. and Wasserburg, G. J. (1978a) Barium and neodymium isotopic anomalies in the Allende meteorite. Astrophysical Journal, 220, L15-L19. 

DePaolo, D Neodymium Isotope Geochemistry, Springer-Verlag New York, Inc. New York, NY, 1988. 

Bertram, C.J. and Elderfield, H. (1993) The geochemical balance of the rare earth elements and neodymium isotopes in the oceans. Geochim. Cosmochim.Acta, 57, 1957-1986. 

Palmer M.R. and Elderfield H. (1986) Rare earth elements and neodymium isotopes in ferromanganese oxide coatings of Cenozoic foraminifera from the Atlantic Ocean. Geochim. Cosmochim. Acta 50, 409-417. 

Vervoort, J.D., Blichert-Toft, J., Patchett, P.J., and Albar de, F. (1997) Hafnium-neodymium isotopic composition of the crust and mantle through time new directions with hafnium whole rock studies. In Seventh Annual V.M. Goldschmidt Conference, 212, LPI Contribution No. 921, Lunar and Planetary Institute Houston. 

Wisshak K., Voss F., Kappeler F., and Kazakov L. (1997) Neutron capture in neodymium isotopes implications for the s-process. Nuclear Phys. A621, 270c—273c. 

MORBs. Diagrams involving neodymium isotopes show more overlap, but Indian Ocean MORBs have many e(Nd) values lower than any sample from the Pacific Ocean. 

Based on neodymium isotopic signatures, Sharma and Wasserburg (1996), Gmau et al. 

Salters V. J. M. and Dick H. J. B. (2002) Mineralogy of the midocean-ridge basalt source from neodymium isotopic composition of abyssal peridotites. Nature 418, 68-72. 

Sharma M. and Wasserburg G. J. (1996) The neodymium isotopic compositions and rare earth patterns in highly depleted ultramafic rocks. Geochim. Cosmochitn. Acta 60, 4537-4550. 

Mica from mantle xenohths is very poor in REE, especially LREE (Table 9). Where reported, Sm/Nd values vary widely both above and below the PUM values (Figure 25) however, the low levels present could be easily influenced by small inclusions or analytical artifacts. Neodymium levels are so low that even the presence of tens of percent mica in a peridotite mineralogy do not significantly influence the neodymium budget of the rock. As such, the presence of mica in a peridotite is not sufficient to generate LREE enrichment and hence its presence alone, is unlikely to cause a bulk peridotite to evolve to enriched neodymium isotopic compositions (Pearson and Nowell, 2002). 

One of the first studies to show this was performed on Kilboume Hole spinel Uierzolites (Jagoutz et al, 1980). Equihbrated neodymium isotopes in orthopyroxene and diopside defined essentially zero age isochrons, consistent with the very recent eruption age of the host volcanic rocks, while strontium isotopes were un-equilibrated. Stolz and Davies (1988) found varying degrees of equihbration between amphibole, clinopyroxene and apatite in peridotite xenoliths from S.E. Australia. Several samples contained coexisting amphibole and clinopyroxene and had almost reached isotopic equilibrium for strontium but displayed disequilibrium relations for lead and neodymium isotopes. This was taken to indicate more rapid diffusion of strontium than lead and neodymium. Some peridotite and eclogite... 

If continental peridotite xenoliths are divided into cratonic and noncratonic compositions, the vast majority of highly enriched neodymium isotope compositions originate in cratonic mantle and very few are evident in noncratonic mantle. Enriched neodymium isotope compositions can also be found in mantle sampled by orogenic peridotites (Reisberg and Zindler, 1986 Pearson et ai, 1993 Chapter 2.04) but not the extreme values evident in cratonic CLM. This is expected, given the great antiquity of cratonic CLM. Further subdivision of cratonic samples (Figure 37) shows... 

Four cratonic, ultradeep xenoliths from S. Africa and Sierra Leone have been analyzed for their strontium and neodymium isotopic compositions (Macdougall and Haggerty, 1999). The neodymium isotopic compositions of minerals from these xenoliths suggest that they were emplaced into the African lithosphere at times ranging from approximately the time of kimberlite emption to hundreds of millions of years earlier. The samples show a complex history of melt... 

---