A comparative study of melilite and fassaite in Types B1 and B2 refractory inclusions

被引:32
|
作者
Simon, SB
Grossman, L
机构
[1] Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA
[2] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA
基金
美国国家航空航天局;
关键词
D O I
10.1016/j.gca.2005.09.018
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Most of the petrologic data available for Type B inclusions comes from Type B1s. Relatively little comes from the B2s, and there has not been a systematic comparison of the properties of their two most abundant minerals. In this work, we document the compositions and zoning patterns of melilite and fassaite in Type B2 inclusions, and compare and contrast them with the features of their counterparts in Type B1 inclusions. We find that melilite compositions in Type B2 inclusions are similar to those of Type B1s, with maximum angstrom k contents of similar to 75 mol % and a positive correlation between angstrom k and Na2O contents. Asymmetrically zoned melilite is common in Type B2s as are melilite grains with reversely zoned regions, and the reversely zoned portions of crystals are thicker than in B1s. In B2s, like B Is, fassaite is zoned with decreasing Ti, Sc, and V oxide contents from cores to rims of grains. Approximately half of the Ti is trivalent, but unlike that in B1s, within fassaite grains in B2s the Ti3+/(Ti3+ + Ti4+) ratio does not decrease from core to rim, and sharp enrichments ("spikes") in Ti3+ and V are not observed. Sector-zoned fassaite is much more common in B2s than in B1s. The differences we observed can be accounted for by the differences in bulk compositions between B1s and B2s. Type B2 inclusions tend to have higher SiO2 contents, hence higher An/Ge component ratios, than Type B1s. Phase equilibria show that, compared to B1s, in B2s less melilite should crystallize prior to the appearance of fassaite, so that in B2s a higher proportion of melilite cocrystallizes with fassaite, causing more of the crystals to be reversely zoned; more melilite crystallizes while adjacent to other crystals, leading to asymmetrical zoning; and with more liquid available, transport of components to growing fassaite occurs more readily than in B1s, facilitating crystal growth and giving rise to sector zoning. The lack of zoning with respect to Ti3+/Ti-101 and the absence of Ti3+-, V-rich spikes suggest that Type B2 melts maintained equilibrium with the nebular gas throughout crystallization, while the interiors of B Is were probably isolated from the gas, perhaps by their metilite mantles. This makes the similarity of Na-angstrom k relationships in B I and B2 melilite difficult to understand, but apparently enclosure by melilite mantles was not necessary for the retention of Na2O during crystallization of Type B refractory inclusions. (c) 2005 Elsevier Inc. All rights reserved.
引用
收藏
页码:780 / 798
页数:19
相关论文
共 50 条
  • [1] Composition and zoning of fassaite in type B2 refractory inclusions
    Simon, SB
    Grossman, L
    GEOCHIMICA ET COSMOCHIMICA ACTA, 2003, 67 (18) : A437 - A437
  • [2] B1 and/or B2? That is the question
    Davenport, William Jeptha
    Pringsheim, Tamara
    HEADACHE, 2022, 62 (09): : 1071 - 1072
  • [3] Occurrence of fumonisin B1 and B2 in beer
    Hlywka, JJ
    Bullerman, LB
    FOOD ADDITIVES AND CONTAMINANTS, 1999, 16 (08): : 319 - 324
  • [4] Photophysics and photochemistry of aflatoxins B1 and B2
    Netto-Ferreira, J. C.
    Heyne, B.
    Scaiano, J. C.
    PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES, 2011, 10 (10) : 1701 - 1708
  • [5] Photophysics and photochemistry of aflatoxins B1 and B2
    J. C. Netto-Ferreira
    B. Heyne
    J. C. Scaiano
    Photochemical & Photobiological Sciences, 2011, 10 : 1701 - 1708
  • [6] Asymmetric Approach to Hyacinthacines B1 and B2
    Reddy, Paidi Venkatram
    Smith, Julien
    Kamath, Anushree
    Jamet, Helene
    Veyron, Amael
    Koos, Peter
    Philouze, Christian
    Greene, Andrew E.
    Delair, Philippe
    JOURNAL OF ORGANIC CHEMISTRY, 2013, 78 (10): : 4840 - 4849
  • [7] Determination of fumonisins B1 and B2 in beer
    Dasko, E
    Rauová, D
    Belajová, E
    Kovác, M
    CZECH JOURNAL OF FOOD SCIENCES, 2005, 23 (01) : 20 - 26
  • [8] Total synthesis of elansolids B1 and B2
    Wang, Liang-Liang
    Kirschning, Andreas
    BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY, 2017, 13 : 1280 - 1287
  • [9] SOURCES OF VITAMINS B1 AND B2 IN FOOD
    Grigoryeva, A. A.
    Mironova, G. E.
    YAKUT MEDICAL JOURNAL, 2019, (04): : 74 - 76
  • [10] On the coverings of Euclidean manifolds B1 and B2
    Chelnokov, G.
    Deryagina, M.
    Mednykh, A.
    COMMUNICATIONS IN ALGEBRA, 2017, 45 (04) : 1558 - 1576