Allanite-(Y) and allanite-(Ce) paragenesis in tourmalinite of the Severnyi pluton, Chukchi Peninsula, and the relationship between yttrium and lanthanides in allanite

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• 作者：V. I. Alekseev ; Yu. B. Marin ; I. M. Gembitskaya
• 关键词：allanite ; (Y) ; allanite ; (Ce) ; yttrium ; lanthanides ; paragenesis ; isomorphism ; tourmalinite ; Chukotka
• 刊名：Geology of Ore Deposits
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：58
• 期：8
• 页码：674-680
• 全文大小：
• 刊物主题：Mineral Resources;
• 出版者：Pleiades Publishing
• ISSN：1555-6476
• 卷排序：58

文摘

The morphology, optical properties, and composition of allanite-(Ce) and allanite-(Y) from raremetal tourmalinite of the Severnyi granitic pluton in the Chukchi Peninsula have been studied, as well as the composition and structure of host metasomatic rocks and the assemblage of rock-forming and accessory minerals. The hydrothermal origin of both allanite species and their stable combination have been established. Allanite-(Y) is partly replaced with allanite-(Ce), and metasomatic rims 2–10 μm wide enriched in LREE around allanite-(Y) have been identified. The degree of isomorphic Y+HREE substitution for LREE is estimated at 16%, on average; the maximum (Y+HREE)/LREE ratio does not exceed 0.25. It is assumed that the transition of allanite-(Y) into allanite-(Ce) might be caused by anincrease in acidity and decrease in aqueous fluid temperature at the late stage of the hydrothermal process.