Anatomy of the Early Proterozoic Nagssugtoqidian orogen, West Greenland, explored by reconnaissance SHRIMP U-Pb zircon dating
Anatomy of the Early Proterozoic Nagssugtoqidian orogen, West Greenland, explored by reconnaissance SHRIMP U-Pb zircon dating
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通过 SHRIMP U-Pb 锆石勘测探索西格陵兰早元古代 Nagssugtoqidian 造山带的解剖
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
A. Nutman
中科院分区：
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作者：
F. Kalsbeek;A. Nutman
对西格陵兰早元古代Nagssugtoqidian造山带的90个样品进行了SHRIMP锆石U-Pb测年，结合以前的年龄和同位素数据以及新的野外观测，获得了造山带一些大型结构的信息：1900-1940 Ma闪长质-英云闪长质幼年弧岩（正的初始Nd_xNd值）在造山带中部和北方的太古宙片麻岩上逆冲超过50 km。太古代和元古代岩石在造山带南缘附近构造交错。区域改造（高级变质作用，剪切作用和地壳熔融）发生在1800-1840 Ma和约。1780年太古代片麻岩之上的幼年元古代弧岩的构造侵位表明，Nagssugtoqidian造山带包含由未知范围的海洋闭合而席卷在一起的不相关岩石切片。
Reconnaissance SHRIMP U-Pb zircon dating of 90 samples from the Early Proterozoic Nagssugtoqidian orogen of West Greenland, together with previous age and isotope data as well as new field observations, yields information on some large-scale structures of the orogen: 1900–1940 Ma dioritic to tonalitic juvenile arc rocks (positive initial ϵ Nd values) are thrust more than 50 km over Archean gneisses in the central and northern portions of the orogen. Archean and Proterozoic rocks are tectonically interleaved near the southern margin of the orogen. Regional reworking (high-grade metamorphism, shearing, and crustal melting) occurred at 1800–1840 Ma and ca. 1780 Ma. Tectonic emplacement of juvenile Proterozoic arc rocks over Archean gneisses suggests that the Nagssugtoqidian orogen contains slices of unrelated rocks swept together by closure of an ocean of unknown extent.