Pan-African granulite-facies metamorphism in the Mozambique Belt of Tanzania: U-Pb zircon geochronology
Pan-African granulite-facies metamorphism in the Mozambique Belt of Tanzania: U-Pb zircon geochronology
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坦桑尼亚莫桑比克带泛非麻粒岩相变质作用：U-Pb锆石年代学
DOI：
10.1144/gsjgs.151.2.0343
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发表时间：
1994
影响因子：
2.7
通讯作者：
J. Lenoir
中科院分区：
文献类型：
--
作者：
S. Muhongo;J. Lenoir
报道了坦桑尼亚东部莫桑比克造山带麻粒岩相岩石中两个新的U-Pb协和锆石年龄。这些岩石被认为是在与碰撞有关的地壳增厚过程中产生的，并在深度侵蚀中被挖掘出来。来自Pare山脉的双辉石麻粒岩样品的上截距年龄为645±10 Ma，而来自Uluguru山脉的麻粒岩相变斜长岩样品的上截距年龄为695±4 Ma。没有发现更古老的地壳物质（晚元古代前）参与的证据。这些锆石数据表明，在泛非造山期（约950 ~约550 Ma）麻粒岩相变质作用的高峰时期结晶，符合俯冲-碰撞环境。
Two new U-Pb concordia zircon ages are reported for granulite-facies rocks from the Mozambique Orogenic Belt in eastern Tanzania. These rocks are thought to have been generated during collision-related crustal thickening process and exhumed by deep erosion. A two-pyroxene granulite sample from the Pare Mountains has yielded a concordia upper intercept age of 645 ± 10 Ma, whereas a granulite-facies meta-anorthosite sample from the Uluguru Mountains has given an upper intercept age of 695 ± 4 Ma. Evidence for the involvement of older crustal material (pre-Late Proterozoic) was not found. These zircon data indicate crystallization during the peak of granulite-facies metamorphism during the Pan-African orogeny (c. 950 to c. 550 Ma) consistent with a subduction-collisional environment.