Jadeite with the Ca-Eskola molecule from an ultra-high pressure metagranodiorite, Dora-Maira Massif, Western Alps

被引：0

作者：

Marco Bruno

Roberto Compagnoni

Takao Hirajima

Marco Rubbo

机构：

[1] Dipartimento di Scienze Mineralogiche e Petrologiche,

[2] University of Turin,undefined

[3] Via Valperga Caluso 35,undefined

[4] 10125 Torino,undefined

[5] Italy,undefined

[6] Department of Geology and Mineralogy,undefined

[7] Graduate School of Sciences,undefined

[8] Kyoto University,undefined

[9] 606-8502 Kyoto,undefined

[10] Japan,undefined

来源：

Contributions to Mineralogy and Petrology | 2002年 / 142卷

关键词：

Oxygen; Significant Shortage; Algebraic Calculation; Total Cation; Igneous Plagioclase;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

A metagranodiorite from the ultra-high pressure (UHP) Brossasco–Isasca Unit (BIU) of the southern Dora Maira Massif, Western Alps, contains relicts of jadeite developed as a pseudomorph after igneous plagioclase during the Alpine UHP metamorphism. The jadeite is characterised by a slight but significant shortage of total cations. On average, for 6 oxygens, the sum of M2 (Na + Ca) cations is 0.93. Careful algebraic calculations on the jadeite end members indicate that Ca and Al combine to form the calcium-Eskola (CaEs) molecule (0.08–0.17) and minor calcium-Tschermack (CaTs) molecule (≤0.03). This is the first report of jadeite with significant amounts of CaEs component from a natural UHP metagranitoid rock. The finding of CaEs molecule in the metagranodiorite is further evidence that the rock experienced UHP metamorphism during the Alpine metamorphism.

引用

页码：515 / 519

页数：4