Crystal chemical control of clinopyroxene-melt partitioning in the Di-Ab-An system: implications for elemental fractionations in the depleted mantle

Journal Article · Sat Aug 01 04:00:00 EDT 1998 · Geochimica et Cosmochimica Acta

DOI:https://doi.org/10.1016/S0016-7037(98)00197-5· OSTI ID:2592

Lundstrom, C. C. ^[1]; Shaw, H. F.; Ryerson, F. J.; Williams, Q.; Gill, J.

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1. LLNL

The partitioning of fifteen trace elements (Rb, Sr, Zr, Nb, Ba, La, Ce, Nd, Sm, Gd, Yb, Hf, Ta, Pb and Th) between clinopyroxene and synthetic melt has been studied in two compositions along an isotherm in the diopside-albite-anorthite ternary at 1 bar pressure. The two compositions correspond to ~ Di₆₅An₃₅ and ~ Di₅₅Ab₄₅ and produce clinopyroxenes distinct in chemistry while melt compositions range from 49 wt % SiO₂ to 61 wt. % SiO₂. The partition coefficients of high field strength elements (HFSE) increase by factors of 2 to 8 in Di-An experiments relative to Di-Ab experiments while other elements show very little change (+/- 20%) between compositions. The change in HFSE partitioning correlates with increases in tetrahedral Al₂O₃ (IVAl) content of clinopyroxenes in the anorthite-bearing experiments. Changes in D_Ta/D_Nb also correlate with IVA1 based on a survey of previously published determinations.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE Office of Defense Programs (DP)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 2592
• Report Number(s): UCRL-JC-131769; PII: S0016703798001975
• Journal Information: Geochimica et Cosmochimica Acta, Journal Name: Geochimica et Cosmochimica Acta Journal Issue: 16 Vol. 62; ISSN 0016-7037
• Publisher: The Geochemical Society; The Meteoritical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY