Non-chondritic Sm/Nd ratio in the terrestrial planets: Consequences for the geochemical evolution of the mantle–crust system

Composition of the Oceanic Crust

“…The isotope data indicate that this depletion has existed for a Nd ratio of the bulk silicate Earth, or at least the observable part of it, is about 0.208, compared with a chondritic value of 0.196 (Boyet and Carlson, 2005;Caro and Bourdon, 2010). This corresponds to a present day e Nd of about þ7.…”

“…It should be pointed out that Lyubetskaya and Korenaga's (2007) estimate of bulk silicate Earth composition, like the earlier ones such as that of McDonough and Sun (1995), is based partly on the assumption of chondritic relative abundances of refractory lithophile elements. However, the nonchondritic 142 Nd/ 144 Nd ratios of all modern terrestrial material (Boyet and Carlson, 2005) make this assumption questionable and raise the possibility that the Earth is depleted in highly incompatible elements relative to chondrites (Caro and Bourdon, 2010;O'Neill and Palme, 2008). If so, MORB and the oceanic crust may be less incompatible element-depleted relative to the bulk silicate Earth than this figure suggests.…”

Major and trace element composition of the high 3He/4He mantle: Implications for the composition of a nonchonditic Earth

“…Nd and 176 Hf/ 177 Hf ratios in high 3 He/ 4 He lavas [e.g., Caro and Bourdon, 2010;Jackson et al, 2010] suggest a history of depletion by melt extraction, a process that increases the Lu/Hf and Sm/Nd ratios in the meltdepleted residue. The association of primitive noble gas isotopic signatures in a mantle reservoir with distinctly nonchondritic refractory element radiogenic isotopic signatures is a paradox that has been the subject of considerable discussion [e.g., Kurz et al, 1982;Hart et al, 1992;Class and Goldstein, 2005;Parman et al, 2005;Caro et al, 2008;Carlson and Boyet, 2008;Gonnermann and Mukhopadhyay, 2009;Caro and Bourdon, 2010;Jackson et al, 2010;Jackson and Carlson, 2011].…”

The Effect of Eluent Concentration on the Separation of Nd with Ln-resin Method

“…Sm-Nd계는 지구 및 태양계의 생성 및 진화와 관 련하여 지구화학적-우주화학적으로 매우 유용하게 활 용되는 방사성 동위원소계이다 (Dickin, 2005;Bouvier et al, 2008;Caro and Bourdon, 2010 (Rollinson, 1993). 그리고Sm-Nd 동위 원소계를 이용한 암석의 연대측정 및 지각의 진화와 같은 지구화학적 연구활용은 열이온화 질량분석기 (Thermal Ionization Mass Spectrometer, TIMS), 다 중 검출기 유도결합플라즈마 질량분석기(MC-ICP-MS) 와 같은 분석 장비를 이용한 Nd, Sm의 동위원소비 측정에 의해 이루어진다 (Tanaka et al, 1987;Tanimizu and Tanaka, 2002;Makishima, 2008;Guo et al, 2010;Murphy et al, 2010 Nd의 동위원소 측정시 직 접적으로 영향을 미칠 수 있다 (Berguland and Wieser, 2011 (Richard et al, 1976;Míková and Denková, 2007).…”