Zircon U-Pb age and Hf isotope evidence for an Eoarchaean crustal remnant and episodic crustal reworking in response to supercontinent cycles in NW India
Zircon U-Pb age and Hf isotope evidence for an Eoarchaean crustal remnant and episodic crustal reworking in response to supercontinent cycles in NW India
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锆石 U-Pb 年龄和 Hf 同位素证据表明印度西北部太古宙地壳遗迹和幕式地壳改造对超大陆旋回的响应
DOI：
10.1144/jgs2016-080
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Chen Wei-Terry
中科院分区：
文献类型：
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作者：
Wang Wei;Cawood Peter A.;P;it Manoj K.;Zhou Mei-Fu;Chen Wei-Terry
印度西北部元古宙德里超群中3.28-2.99 Ga锆石的TDM 2（3.8-3.2 Ga）为年轻地壳的形成和老地壳的改造提供了证据。 2.86- 2.71Ga锆石亏损的类地幔εHf（t）值（+7.2 ~+5.6）表明，在这一时期有年轻地壳的形成，并在2.71Ga停止。 2.66-2.34、2.11-2.01和1.60-1.37 Ga的大规模岩浆活动主要是对不同年龄的先存地壳的改造，后两期伴随着年轻地壳的形成。 始新世的年龄为3671 ± 15 Ma，是在印度西北部发现的最古老的年龄。 在超大陆组装过程中形成的锆石具有正到负的εHf（t）值，这表明年轻和古老地壳的参与，而在超大陆合并之后结晶的锆石的εHf（t）值大部分为正，这表明主要是年轻地壳的参与。碎屑岩年龄模式与构造岩浆事件的相关性表明，在努纳造山过程中，北方印度板块与华南华夏地块处于共轭位置。补充资料：补充资料，包括与实验室和样品制备方法有关的详细元数据，分析样品的U-Pb和Lu-Hf同位素组成以及标准品，可在https://doi.org/10.6084/m9.figshare.c.3711847上获得
Scattered TDM2(3.8–3.2 Ga) for 3.28–2.99 Ga zircons from the Proterozoic Delhi Supergroup in northwestern India provide evidence for generation of juvenile crust and reworking of older crust. Depleted mantle-likeεHf(t)values (+7.2 to +5.6) for 2.86–2.71 Ga zircons indicate that generation of juvenile crust occurred during this period and ceased at 2.71 Ga. Extensive magmatism at 2.66–2.34, 2.11–2.01 and 1.60–1.37 Ga was dominated by reworking of pre-existing crust with variable ages, and the last two periods were accompanied by formation of juvenile crust. An Eoarchaean age of 3671 ± 15 Ma represents the oldest age found in NW India. Zircons formed during supercontinent assembly have positive to negativeεHf(t)values, suggesting involvement of juvenile and ancient crust, whereas largely positiveεHf(t)values for zircons crystallized subsequent to supercontinent amalgamation suggest involvement of predominantly juvenile crust. Correlation of detrital age patterns and tectonomagmatic events indicates a conjugate position for northern Indian and the Cathaysia Block of South China during the assembly of Nuna. The South China Block remained juxtaposed to India until its separation from Pangaea in the late Palaeozoic.Supplementary material:Supplementary data, including detailed metadata related to laboratory and sample preparation methods, U-Pb and Lu-Hf isotopic compositions of the analyzed samples and standards are available at https://doi.org/10.6084/m9.figshare.c.3711847