Mineral chemistry characteristics of garnets in diamondiferous basite of Lan'gan area, Anhui Province
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摘要:
在中国东部皖北地区分布着新元古代镁铁质岩,其中一些碱性基性岩为金刚石的赋矿岩石。为了确定安徽栏杆金刚石矿区的石榴子石种类,对矿区内不同类型的石榴子石进行系统采样,测定了62件石榴子石微区化学成分。结果显示,安徽栏杆石榴子石矿物化学式A32+B23+(SiO4)3中的A组阳离子由Mg2+、Fe2+和Ca2+离子占位,B主要由Al3+、Fe3+、Mn3+和Cr3+离子占位,三价阳离子主要为Al3+,二价阳离子主要为Ca2+,表明研究区石榴子石主要为钙铝-钙铁-镁铝石榴子石系列。在62个样品中,发现了超硅石榴子石。经过计算其形成的压力范围为12.1~12.8GPa,深度可达300km。
Abstract:The mafic rock is exposed in northern Anhui Province, and some of them are diamondiferous rocks. In order to determine the type of garnets, the authors systematically sampled the garnets in diamondiferous basite in Lan'gan area. The MgO, SiO 2, FeO, TiO2, Al2O3, Cr2O3, CaO, MnO values of 62 single crystal garnets in this area were measured by electron microprobe spectrometer. The results show that the chemical formula of garnet group minerals is A32+B23+(SiO4)3. Group A cations are composed of Mg2+, Fe2+ and Ca2+. Group B cations are composed of Al3+, Fe3+, Mn3+ and Cr3+. The trivalent cation is mainly Al3+ while divalent cation is mainly Ca2+. It is inferred that grossularite-andradite-almandine group is the primary class in the Lan'gan area. The high calcium silicate iron garnet (majorite) was found in 62 samples. According to the composition of these majorities in Lan'gan area, the garnet of the diamondiferous basite has formation pressure of 12.1~12.8GPa, and the depth is up to 300km.
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Keywords:
- garnet /
- majorite /
- diamondiferous rocks /
- Lan'gan area /
- Anhui Province
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图 4 石榴子石端元组分三角图(据参考文献[13]修改)
A-金伯利岩、玄武岩中的包体及超镁铁岩中的层状榴辉岩体; B-角闪岩相或麻粒岩相地体的副片麻岩或混合岩带状榴辉岩体; C-阿尔卑斯型变质岩或蓝闪片岩中的带状透镜状榴辉岩。Prp-镁铝榴石; Grs-钙铝榴石; Adr-钙铁榴石; Sps-锰铝榴石; Alm-铁铝榴石
Figure 4. Triangular diagram of endmember components of garnet
表 1 石榴子石主量元素含量
Table 1 Composition of major elements of garnets
% 样号 G3c-1 G3c-2 G3c-3 G3c-4 G3c-5 G3c-6 G3c-7 G3c-8 G3c-9 G3c-l0 G3c-11 G3c-12 G3c-13 G3c-14 G3c-15 G3c-16 G3c-17 G3c-18 G3c-19 G3c-20 G3c-21 G3c-22 G3c-23 G3c-24 G3c-25 G3c-26 G3c-27 G3c-28 G3c-29 G3c-30 G3c-31 G3c-32 G3c-33 G3c-34 G3C-35 G3c-36 G3c-37 G3c-38 G3c-39 G3c-40 G3h-1 G3h-2 G3h-3 G3h-4 G3h-5 G3h-6 G3h-7 G3h-8 G3h-9 G3h-10 G3h-11 G3h-12 G3h-13 G3H-14 G3h-15 G3h-16 G3h-17 G3h-18 G3h-19 G3h-20 G3h-21 G3h-22 SiO2 37.91 37.87 37.80 37.92 37.24 37.77 36.96 37.47 37.46 37.44 37.42 37.19 37.91 37.22 37.80 38.70 37.27 37.10 37.53 36.80 37.39 37.76 37.63 37.95 37.46 37.78 37.40 37.45 37.75 37.54 37.40 37.26 38.24 36.79 37.51 38.53 37.02 37.66 42.53 37.95 37.51 37.80 37.59 37 37 37.93 38 08 37 98 37 98 37.39 37.31 37 74 37.50 37.70 38.10 38 44 37.55 37.59 38.36 37 70 38 30 37.77 37.97 TiO2 0.42 0.41 0.30 0.20 0.57 0.66 0.82 0.52 0.42 0.39 0.74 0.27 0.38 0.36 0.45 0.36 0.42 0.07 0.80 0.54 0.40 0.51 0.54 0.60 0.63 0.28 0.52 0.27 0.28 0.64 0.71 0.61 0.44 0.33 0.58 0.48 0.39 0.53 0.38 0.44 0 37 0.89 0.88 0.36 0.51 0.43 0.56 0 18 0 56 0.69 0.38 0.41 0.52 0 88 0.64 0.53 0 31 0.76 0.65 0.55 0 38 0 39 Al2O3 16.37 16.50 15.68 15.53 15.73 16.93 14.82 16.51 12.85 14.63 15.19 14.09 15.73 14.85 15.37 16.64 13.08 9.85 15.20 14.47 14.54 16.38 16.44 16.42 16.93 15.09 15.32 12.98 15.14 14.92 15.42 15.07 16.87 15.79 13.45 17.07 15.05 15.85 10.93 16.01 15.80 17.11 16.45 15.04 16.21 15.26 16.78 15.35 15.80 16.71 14.65 15.35 15.92 15.72 16.99 16.27 15.46 16.70 16.87 17.54 16.24 16.31 FeO 7.51 6.84 8.72 8.87 7.49 6.30 9.02 6.93 11.84 10.15 S.72 10.88 8.50 9.74 8.62 7.05 11.87 15.96 8.43 9.62 9.79 7.60 7.69 6.95 6.99 9.06 8.56 12.14 9.14 9.16 8.20 8.98 7.13 8 84 11.16 6.78 9.32 8.36 10.18 8.06 848 6.29 7.03 9.72 7.63 8.95 7.24 9.28 8.29 7.20 9.95 8.49 8.01 7.63 6.60 7.43 9.11 6.93 6.99 6.22 7.92 7.79 MnO 0.22 0.13 0.18 0.13 0.20 0.12 0.20 0.15 0.17 0.17 0.15 0.14 0.13 0.05 0.08 0.15 0.09 0.05 0.12 0.06 0.13 0.07 0.13 0.15 0.21 0.14 0.18 0.12 0.15 0.02 0.19 0.16 0.06 0.09 0.07 0.07 0.27 0.20 0.09 0.08 0 10 0.09 0.11 0.24 0.12 0.13 0.17 0 17 0 10 0 12 0.21 0 17 0 06 0 12 0.06 0.24 006 0 13 0.13 0.18 021 0 18 MgO 0.14 0.17 0.17 0.11 0.20 0.20 0.21 0.22 0.15 0.14 0.21 0.16 0.11 0.14 0.14 0.20 0.15 0.07 0.22 0.18 0.13 0.22 0.29 0.19 0.22 0.15 0.20 0.09 0.13 0.18 0.18 0.18 0.15 0.19 0.17 0.22 0.17 0.22 3.97 0.16 0 15 0.24 0.24 0.16 0.16 0.14 0.25 0.14 0 16 0.25 0.14 0.16 0.20 0.21 0.21 0.24 0.15 0.22 0.21 0.22 0 16 0.17 CaO 36.66 36.89 36.62 36.48 36.60 36.57 36.66 36.81 36.17 36.58 36.47 36.39 36.51 36.57 36.57 36.41 36.18 35.60 36.52 36.37 36.68 36.88 36.73 36.90 36.87 36.60 36.53 36.21 36.78 36.49 36.90 36.64 37.00 36.40 36.18 37.05 36.31 36.49 32.12 36.57 36.72 36.85 36.79 35.96 36.34 36.38 36.84 36.47 36.77 36.93 36.27 36.48 36.75 36.78 36.88 36.70 36.48 36.77 36.7! 36.92 36.65 36.72 Na2O 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.02 0.00 0.01 0.01 0.00 0.00 0.01 0.03 0.00 0.02 0.00 0.00 0.00 0.01 0.01 0.04 0.03 0.01 0.00 0.00 0.00 0.02 0.00 0.00 0.12 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.03 0.03 0.01 0.01 0.00 0.02 0.02 0.03 0.01 0.00 0.01 0.02 0.00 0.02 K20 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.02 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 ZnO 0.04 0.04 0.05 0.07 0.05 0.00 0.11 0.00 0.00 0.00 0.03 0.00 0.00 0.05 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.03 0.07 0.00 0.07 0.04 0.01 0.08 0.02 0.09 0.00 0.06 0.00 0.00 0.05 0.06 0.00 0.02 0.00 0.00 0.03 0.02 0.03 0.08 0.00 0.05 0.00 0.00 0.00 0.02 0.07 0.05 0.00 0.06 0.04 0.03 0.07 0.05 0.05 003 0.00 Cr2O3 0.00 0.00 0.01 0.00 0.00 0.06 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.04 0.00 0.00 0.04 0.07 0.00 0.00 0.00 0.05 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.04 0.01 0.07 0.00 0.00 0.08 0.03 0.04 0.00 0.03 0.13 0.01 0.00 0.00 0.02 0.01 0.02 0.00 0.01 0.00 0.00 0.05 0.00 0.04 0.04 0.00 0.00 0.03 0.00 NiO 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.05 0.02 0.00 0.00 0.05 0.08 0.00 0.00 0.07 0.00 0.00 0.00 0.00 0.07 0.00 0.00 0.00 0.05 0.00 0.00 0.06 0.01 0.00 0.02 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.02 0.00 0.03 0.00 0.00 0.03 0.00 0.00 0.01 0.00 0.02 0.05 0.04 0.05 0.00 0.00 总计1 99.29 98.X8 99.55 99.29 98.08 9S.62 98.79 98.59 99.06 99.50 99.02 99.13 99.27 98.98 99.11 99.62 99.07 98.69 98.92 98.09 99.06 99.48 99.48 99.37 99.32 99.17 98.74 99.34 99.46 99.00 99.18 98.94 99.94 98.49 99.13 100.34 98.59 99.38 99.31 99.17 99.30 99.15 99 04 98 99 99.36 99.91 99.58 99.14 99.23 99 37 98 68 99.23 99.45 99 94 99 02 99.25 100.02 99.34 100.04 99.38 99.55 Fe2O3 7.38 7.13 8.38 8.38 7.88 6.39 9.22 7.21 11.23 9.65 8.61 10.27 8.05 9.34 8.39 6.71 11.12 14.57 8.44 9.44 9.58 7.56 7.58 7.23 7.04 8.84 8.53 11.30 8.96 8.87 8.53 8.91 6.97 8.41 10.49 6.68 9.04 8.08 11.16 7.71 8 21 6 46 7.20 8.88 7.30 8.44 7.16 8 66 8 19 7.30 9.32 843 7 94 7.77 6.55 7.57 8 56 6 86 6.91 6.22 767 7 56 FeO 0.87 0.42 1.18 1.33 0.40 0.56 0.73 0.44 1.73 1.47 0.98 1.63 1.25 1.34 1.07 1.01 1.86 2.85 0.83 1.12 1.17 0.80 0.87 0.44 0.65 1.10 0.88 1.97 1.08 1.17 0.52 0.96 0.86 1.28 1.72 0.76 1.18 1.09 0.13 1.13 1.09 0.48 0.56 1.73 1.06 1.35 0.80 1.48 0.92 0.62 1.56 0.91 0.86 0.64 0.71 0.62 1.41 0.76 0.77 0.62 1.02 0.99 总计2 100.01 99.58 100.38 100.13 98.87 99.26 99.72 99.32 100.18 100.47 99.87 100.16 100.07 99.91 99.93 100.29 100.16 100.15 99.76 99.03 100.01 100.21 100.24 100.06 100.01 100.06 99.59 100.46 100.35 99.85 100.00 99.83 100.63 99.33 100.18 100.99 99.49 100.18 100.07 99.99 99.95 99.86 99.93 99.71 100.21 100.61 100.45 99.93 99.93 100.29 99.51 100.02 100.21 100.57 99.75 100.10 100.71 100.02 100.64 100.15 100.28 Si 3.00 3.01 3.01 3.03 3.00 2.99 2.98 2.99 3.05 3.01 3.00 3.01 3.02 3.00 3.02 3.04 3.04 3.11 3.01 3.00 3.01 2.99 2.98 3.00 2.96 3.03 3.00 3.05 3.02 3.01 2.99 2.99 3.00 2.97 3.04 3.01 2.99 3.00 3.31 3.01 3 01 2.97 2.99 3.02 3.02 2.99 2.98 2.98 3.01 3.01 3.03 2.99 3 03 2.99 2.96 3.03 3 01 3.00 3.02 3.01 2 99 301 Al(T) 0.05 0.05 0.05 0.04 0.06 0.05 0.09 0.07 0.03 0.06 0.06 0.06 0.04 0.07 0.04 0.01 0.05 0.01 0.06 0.07 0.06 0.06 0.07 0.05 0.09 0.04 0.06 0.04 0.05 0.05 0.07 0.07 0.05 0.10 0.04 0.04 0.07 0.06 0.00 0.04 007 0.07 0.07 0.06 0.04 0.03 0.06 0.04 0.07 0.09 0.04 0.05 0.06 0.04 0.04 0.07 0 06 0.04 0.07 0.06 0.06 0.05 Al(O) 1.48 1.50 1.42 1.42 1.43 1.53 1.32 1.48 1.20 1.32 1.37 1.28 1.44 1.34 1.41 1.53 1.21 0.96 1.38 1.31 1.32 1.46 1.46 1.48 1.49 1.38 1.39 1.21 1.38 1.36 1.38 1.36 1.51 141 1.25 1.53 1.36 1.43 1.00 1.45 1 42 1.52 1.46 1.37 1.48 1.41 1.49 1.40 1.41 1.47 1.34 1 40 1 44 1 43 1.53 1.46 1.40 1.50 1.50 1.56 1.46 1.47 Ti 0.02 0.02 0.02 0.01 0.03 0.04 0.05 0.03 0.03 0.02 0.04 0.02 0.02 0.02 0.03 0.02 0.03 0.00 0.05 0.03 0.02 0.03 0.03 0.04 0.04 0.02 0.03 0.02 0.02 0.04 0.04 0.04 0.03 0.02 0.03 0.03 0.02 0.03 0.02 0.03 0.02 0.05 0.05 0.02 0.03 0.03 0.03 0.01 0.03 0.04 0.02 0.02 0.03 0.05 0.04 0.03 0.02 0.04 0.04 0.03 0.02 0.02 Cr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Fe3+ 0.43 0.42 0.49 0.49 0.47 0.38 0.55 0.42 0.67 0.57 0.51 0.61 0.47 0.55 0.49 0.39 0.66 0.S8 0.50 0.56 0.57 0.44 0.44 0.42 0.41 0.52 0.50 0.67 0.53 0.52 0.50 0.53 0.40 0.50 0.62 0.39 0.54 0.47 0.64 0.45 048 0.38 0.42 0.53 0.43 0.50 0.42 0.51 0 48 043 0.55 0.50 0 47 0.45 0.38 0.45 0 50 0.40 0.40 0.36 0.45 0.44 Fe2+ 0.06 0.03 0.08 0.09 0.03 0.04 0.05 0.03 0.11 0.10 0.06 0.11 0.08 0.09 0.07 0.07 0.12 0.19 0.05 0.07 0.08 0.05 0.06 0.03 0.04 0.07 0.06 0.13 0.07 0.08 0.03 0.06 0.06 0.08 0.11 0.05 0.08 0.07 0.01 0.07 0.07 0.03 0.04 0.11 0.07 0.09 0.05 0.10 0.06 0.04 0.10 0.06 0.06 0.04 0.05 0.04 009 0.05 0.05 0.04 0.07 0.06 Mn 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00 0.00 0.01 0.01 0.00 0.01 0.00 0.01 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00 0.01 0.01 0.00 0.01 0.00 0.00 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00 0.01 0.00 0.02 0.00 0.01 0.01 0.01 0.01 0.01 Mg 0.02 0.02 0.02 0.01 0.02 0.02 0.03 0.03 0.02 0.02 0.02 0.02 0.01 0.02 0.02 0.02 0.02 0.01 0.03 0.02 0.02 0.03 0.03 0.02 0.03 0.02 0.02 0.01 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.03 0.02 0.03 0.45 0.02 0.02 0.03 0.03 0.02 0.02 0.02 0.03 0.02 0.02 0.03 0.02 0.02 0.02 0.02 0.02 0.03 0.02 0.03 0.02 0.03 0.02 0.02 Ni 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 000 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Zn 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Ca 3.06 3.08 3.06 3.05 3.09 3.06 3.10 3.09 3.07 3.07 3.07 3.08 3.05 3.09 3.07 3.01 3.07 3.08 3.07 3.10 3.09 3.07 3.06 3.07 3.07 3.07 3.08 3.07 3.08 3.07 3.10 3.09 3.06 3.08 3.06 3.05 3.07 3.05 2.61 3.05 3.08 3.06 3.07 3.03 3.04 3.04 3.05 3.05 3.08 3.08 3.05 3.07 3.07 3.06 3.04 3.07 3.06 3.04 3.06 3.04 3.06 3.06 总计 8.09 8.08 8.10 8.09 8.09 8.07 8.11 8.09 8.11 8.11 8.09 8.12 8.09 8.11 8.09 8.06 8.11 8.13 8.09 8.11 8.11 8.09 8.10 8.08 8.10 8.10 8.10 8.12 8.10 8.09 8.10 8.10 8.08 8.12 8.10 8.07 8.11 8.09 7.97 8.08 8 10 8.07 8.08 8.11 8.08 8.08 8.09 8.10 8.10 8.10 8.10 8 10 8 09 8.07 8.07 8.09 8 10 8.07 8.09 8.07 809 8.09 Alm 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 000 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Adr 22.36 21.63 25.44 25.62 24.22 19.37 28.43 21.81 35.82 29.63 26.54 31.77 24.64 28.64 25.85 20.46 35.19 48.58 26.14 29.35 29.60 22.76 22.75 21.91 21.23 27.21 26.23 35.74 27.42 27.52 26.09 27.39 20.88 25.79 33.23 19.96 27.73 24.56 39.34 23.50 24.88 19.41 21.81 27.25 22.34 26 10 21.40 26 48 24.85 22.10 2S 89 25.95 24.15 23.99 19 72 22.91 26.10 20.76 20.74 18 45 23.16 22.83 Grs 76.58 77.37 73.42 73.64 74.52 79.36 70.24 76.98 63.16 69.42 72.17 67.25 74.62 70.67 73.42 78.28 64.00 51.02 72.57 69.58 69.54 76.20 75.81 76.85 77.42 71.84 72.54 63.59 71.72 71.72 72.75 71.43 78.41 73.10 65.89 78.79 70.96 74.11 41.64 75.58 74.15 79.42 76.88 71.15 76.70 73.02 77.26 72.51 74.24 76.60 70.06 72.99 74.90 74.86 79.19 75.59 73.04 77.96 78.15 80.29 75.66 76.09 pyp 0.58 0.70 0.69 0.44 O.SO 0.80 0.87 0.88 0.62 0.56 0.S5 0.66 0.46 0.58 0.56 0.81 0.61 0.29 0.89 0.73 0.55 0.89 1.14 0.76 0.87 0.61 0.83 0.39 0.53 0.72 0.73 0.72 0.58 0.78 0.69 0.88 0.68 0.88 18.49 0.66 0.61 0.96 0.96 0.64 0.64 0.58 0.97 0.57 0.65 0.98 0.56 0.64 0.82 0.87 0.82 0.96 0.60 0.87 0.84 0.86 0.62 0.68 Sps 0.49 0.30 0.42 0.31 0.46 0.27 0.47 0.33 0.40 0.39 0.36 0.32 0.29 0.11 0.17 0.33 0.20 0.12 0.28 0.13 0.31 0.15 0.30 0.34 0.48 0.31 0.41 0.28 0.34 0.05 0.43 0.37 0.13 0.20 0.15 0.15 0.63 0.45 0.24 0.19 0.22 0.21 0.26 0.54 0.28 0.31 0.37 0 38 0.23 0.27 0.48 0.38 0 14 0.27 0.13 0.54 0 15 0 28 0.28 0.40 0.47 0.40 Uvt 0.00 0.00 0.03 0.00 0.00 0.20 0.00 0.00 0.00 0.00 0.09 0.00 0.00 0.01 0.00 0.12 0.00 0.00 0.13 0.22 0.00 0.00 0.00 0.14 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.08 0.00 0.13 0.03 0.22 0.00 0.00 0.30 0.08 0 13 0.00 0.09 0.42 0.04 0.00 0.00 0.06 0.03 0.05 0.01 0.04 0.00 0.00 0.14 0.00 0 12 0.12 0.00 0.00 0.10 0.00 注:Alm—铁铝榴石;Prp—镁铝榴石;Sps—锰铝榴石;Grs—钙铝榴石;Adr—钙铁榴石;Uvt—钙铬榴石 表 2 Dawson-Stephens分类石榴子石产状及特征氧化物平均值[10]
Table 2 Oxide averages of garnets of different modes of occurrence in Dawson-Stephens classification
% 编号 矿物名称 TiO2 Cr2O3 FeO MgO CaO 产状 1 钛-镁榴石 0.58 1.34 9.32 20.0 4.82 K, GL, GOW, D 2 高钛-镁铝榴石 1.09 0.91 9.84 20.3 4.52 K 3 钙-镁铝榴石-铁铝榴石 0.31 0.30 16.49 13.35 6.51 K, GL, GOW, EC, D 4 钛、钙、镁-铁铝榴石 0.90 0.08 17.88 9.87 9.41 K, EC, D 5 镁-铁铝榴石 0.05 0.03 28.23 7.83 2.44 K, EC, D 6 镁铝榴石-钙铝榴石-铁铝榴石 0.24 0.27 10.77 10.38 14.87 GP, EC, GR 7 铁-镁-钙铬榴石-钙铝榴石 0.29 11.52 5.25 8.61 21.60 K, GS 8 铁-镁-钙铝榴石 0.25 0.04 6.91 4.69 24.77 GR 9 铬镁铝榴石 0.27 3.47 8.01 20.01 5.17 K, GL, GOW, GH, EC, D 10 低钙-铬-镁铝榴石 0.04 7.73 6.11 23.16 2.13 K, GS, D 11 钙铬榴石-镁铝榴石 0.51 9.55 7.54 15.89 10.27 K, GL, GWH, D 12 镁铬榴石-钙铬榴石-镁铝榴石 0.18 15.94 7.47 15.40 9.51 K, GS 注:K—金伯利岩;GL—石榴二辉橄榄岩;GH—石榴方辉橄榄岩;GD—石榴纯橄岩;GS—石榴蛇纹岩;GOW—石榴橄榄二辉岩;GP—石榴辉石岩;GWH—石榴易剥橄榄岩;GR—辉榴蓝晶岩;EC—榴辉岩;D—金刚石包体 表 3 栏杆含金刚石母岩中石榴子石分子式
Table 3 Formula characteristics and types of garnet in kimberlite from Lan'gan
石榴子石名称 代表样品分子式 件数 钙铁镁-铝铁榴石 (Ca3.06Fe0.06Mg0.02)3.14(Al1.48Fe0.43Ti0.02)1.93Si2.95O12 57 超硅钙铁榴石 (Ca3.07Fe0.11Mg0.02)3.2(Al1.2Fe0.67Ti0.03Si0.05)1.95Si3O12 1 (Ca3.07Fe0.13Mg0.01)3.21(Al1.21Fe0.67Ti0.02Si0.05)1.95Si3O12 1 (Ca3.08Fe0.19Mg0.01)3.28(Al0.96Fe0.88Si0.11)1.95Si3O12 1 (Ca2.616Mg0.45Fe0.01)3.07(Al1Fe0.64Ti0.02Mn0.01Si0.31)1.98Si3O12 1 钙铁镁-铝铁锰铬榴石 (Ca3.03Fe0.11Mg0.02)3.17(Al1.48Fe0.53Ti0.02Mn0.02Cr0.01)2.06Si2.94O12 1 -
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