Uranium‐lead zircon ages from the Median Tectonic Zone, New Zealand
Uranium‐lead zircon ages from the Median Tectonic Zone, New Zealand
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新西兰中位构造带的铀铅锆石年龄
DOI：
10.1080/00288306.1994.9514630
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发表时间：
1994
影响因子：
2.2
通讯作者：
J. Mattinson
中科院分区：
文献类型：
--
作者：
D. Kimbrough;A. Tulloch;D. Coombs;C. Landis;M. Johnston;J. Mattinson
新西兰中央构造带（MTZ）是南岛和斯图尔特岛中生代俯冲相关I型深成岩、火山岩和沉积岩的总体北向带，将东部省布鲁克街地体的二叠纪地层与西部省的下古生代至中古生代冈瓦纳大陆边缘组合分开。本文报道了30个岩石中锆石的高精度同位素稀释U/Pb年龄。在氢氟酸中对锆石进行预消化浸出，通过去除常见的Pb和溶解更多的可溶性高U域（这些高U域受相对较新的Pb损失影响更大），产生了更一致的残留物。结果表明，MTZ岩浆活动的年龄至少为早三叠世至早白垩世（247-131 Ma），中侏罗世存在明显的岩浆活动空区。三叠纪岩体往往出现在MTZ的东侧，它们侵入纳尔逊和峡湾东部MTZ的火山/沉积序列。这些序列依次被...
Abstract The Median Tectonic Zone (MTZ) of New Zealand is a generally north trending belt of Mesozoic subduction‐related I‐type plutonic, volcanic, and sedimentary rocks in South Island and Stewart Island that separates Permian strata of the Eastern Province Brook Street Terrane from lower to mid‐Paleozoic Gondwana margin assemblages of the Western Province. High‐precision isotope dilution U/Pb ages of zircons from 30 rocks are reported. Pre‐digestion leaching of zircon in hydrofluoric acid yielded significantly more concordant residues by removing common Pb and dissolving more soluble high‐U domains that have been more affected by relatively recent Pb loss. The results show that MTZ magmatism ranges in age from at least Early Triassic to Early Cretaceous (247–131 Ma), with a pronounced gap in the Middle Jurassic. Triassic plutons tend to occur on the eastern side of the MTZ, and they intrude volcanic/sedimentary sequences of the MTZ in Nelson and eastern Fiordland. These sequences are in turn intruded by...