Finding of corundum-bearing rocks in the Lapland granulite belt

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• 作者：E. N. Terekhov ; T. F. Shcherbakova ; A. N. Konilov
• 刊名：Doklady Earth Sciences
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：470
• 期：1
• 页码：914-920
• 全文大小：1,751 KB
• 刊物主题：Earth Sciences, general;
• 出版者：Springer US
• ISSN：1531-8354
• 卷排序：470

文摘

Corundum-bearing rocks are described for the first time in the Kandalaksha structure of the Lapland granulite belt. Corundum is confined to rocks of two types: metagabbro‒anorthosites constituting lenses among metaanarthosites of the Kandalaksha massif and basic granulites. Corundum crystals (up to 200 μm long) occur in plagioclase and garnet and differ from each other depending on the host mineral, which serves as evidence against their xenogenic nature. Some corundum crystals exhibit an axial zone, which may indicate their crystallization from the gaseous phase. Corundum-bearing rocks are accompanied by piclogites (pyroxene‒garnet varieties with olivine). Piclogites and their minerals (clinopyroxene, garnet) are characterized by a positive Eu anomaly, which implies rock reworking by fluids during corundum formation, when deep-seated complexes were subjected to exhumation.