Kiglapait Geochemistry IV: The Major Elements
Kiglapait Geochemistry IV: The Major Elements
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DOI：
10.1016/0016-7037(81)90254-4
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发表时间：
1981-03
影响因子：
5
通讯作者：
S. Morse
中科院分区：
文献类型：
--
作者：
S. Morse
Kiglapait岩体的总体成分为SiO2 47.46（31）。TiO20.81（20），Al2O319.46（48），Fe2O31.91（46），FeO9.36（36），MnO0.15（01）. MgO 8.04（21），CaO 9.27（46）。Na2O3.13（05），K2O0.22（01），P2O5，0.09（01），BaO0.02（01）.总计99.98wt%（括号中最后两位小数的估计标准偏差）。CIPW标准为isap 0.34，mt 2.78，il 1.52，or 1.11，ab 26.27，an 38.64，（fsp 66.47），di 5.38，hy 2.45，ol 21.58。摩尔X An为0.58;摩尔X fo为0.65。计算液体中氧化物的变化曲线用本系列以前的文章中所示的岩相变化作了详细的解释。Kiglapait FeO+ MnO：MgO：碱（FMA）的趋势达到更高的铁浓度比Skaergaard液体，并构成了一个新的限制情况下，芬纳趋势的分离结晶，这意味着低氧逸度和二氧化硅活性。终期Kiglapait正铁岩位于FeO+ MnO-碱性边线上，基本上不含MgO。除了K和K Rb。Kiglapait的成分在实验误差范围内与附近Hettasch侵入体的冷却边缘相同（贝格，1980.），但轻微的系统差异表明，Hettasch组合物的分馏程度略高，或代表了在源头处熔化的较小部分。两者都是低普通辉石troctolite组合物，它们需要troctolite母液。这些液体与普通的富辉石玄武岩有关，通过添加尖晶石，它们意味着源中单斜辉石的耗尽。Kiglapait和Hettasch的成分除了低普通辉石和高Al 2 O3外，与现代MORB相似，表明是一个亏损的源区。
The summed bulk composition of the Kiglapait intrusion is SiO 2 47.46 (31). TiO 2 0.81 (20), Al 2 O 3 19.46 (48), Fe 2 O 3 1.91 (46), FeO 9.36 (36), MnO 0.15 (01). MgO 8.04 (21), CaO 9.27 (46). Na 2 O 3.13 (05), K 2 O 0.22 (01), P 2 O 5, 0.09 (01), and BaO 0.02 (01). total 99.98 wt%(estimated standard deviations of the last two decimals in parentheses). The CIPW norm isap 0.34, mt 2.78, il 1.52, or 1.11, ab 26.27, an 38.64,(fsp 66.47), di 5.38, hy 2.45, ol 21.58. Molar X An is 0.58; molar x fo is 0.65. The variation curves for oxides in calculated liquids are explained in detail by the petrographic variations shown in earlier papers of this series. The Kiglapait FeO+ MnO: MgO: Alkalies (FMA) trend reaches higher iron concentrations than the Skaergaard liquid and constitutes a new limiting case of the Fenner trend of fractional crystallization, implying low oxygen fugacity and silica activity. The end-stage Kiglapait ferrosyenite lies on the FeO+ MnO-Alkalies sideline, being essentially devoid of MgO. Except in K and K Rb. the Kiglapait composition is the same within experimental error as the chilled margin of the nearby Hettasch intrusion (BERG, 1980.), but slight systematic differences show that the Hettasch composition is slightly more fractionated or represents a smaller fraction of melting at the source. Both are low-augite troctolite compositions, and they require troctolitic parent liquids. Such liquids are related to common augite-rich basalts by addition of spinel, and they imply exhaustion of clinopyroxene in the source. Except for their low augite and high Al 2 O 3, the Kiglapait and Hettasch compositions resemble modern MORB and suggest a depleted source.