Deciphering the Mesoarchean to Neoarchean history of crustal growth and recycling in the Caochang region of the Eastern Hebei Province, North China Craton using combined zircon U-Pb and Lu-Hf isotope analysis
Deciphering the Mesoarchean to Neoarchean history of crustal growth and recycling in the Caochang region of the Eastern Hebei Province, North China Craton using combined zircon U-Pb and Lu-Hf isotope analysis
复制标题
锆石U-Pb、Lu-Hf联合同位素分析破译华北克拉通冀东草场地区中太古代至新太古代地壳生长与再循环历史
DOI：
10.1016/j.lithos.2019.03.013
复制
发表时间：
2019
期刊：
影响因子：
3.5
通讯作者：
Guo Jinghui
中科院分区：
文献类型：
--
作者：
Liou Peng;Guo Jinghui
在太古代的古宙中，太古代（3.0-2.5 Ga）的结束以花岗岩类岩石的性质和岩石成因的相当大的多样性为标志。本文报道了冀东草场地区一系列中太古代-新太古代闪长岩、英云闪长岩-奥长花岗岩-花岗闪长岩（TTG）和花岗质片麻岩的研究。结合锆石U-Pb和Lu-Hf同位素分析和CL成像分析，揭示了3次主要岩浆事件（3.2- 3.0Ga、2.9- 2.8Ga、~ 2.5Ga）和1次主要变质叠加事件（~ 2.5Ga）。不同锆石畴的时间关系表明，晚新太古代地壳物质在形成后立即进行再循环或改造，随后发生~ 2.5Ga重结晶变质作用，大量幔源镁铁质岩石表明2.5- 2.6Ga是冀东地区重要的地壳添加期。冀东地区Hf模式年龄的峰值和广泛分布的中太古代或古太古代地壳物质可能是新太古代之前又一个重要的地壳添加期。
In Archean cratons, the end of the Archean aeon (3.0–2.5 Ga) is marked by a considerable diversification in both the nature and petrogenesis of granitoid rocks. We reported the studies of a series of Mesoarchean-Neoarchean diorite and tonalite–trondhjemite–granodiorite (TTG) and granitic gneisses in the Caochang area, Eastern Hebei region of the North China Craton. Combined zircon U-Pb and Lu-Hf isotope analyses and CL imaging analysis reveal three major magmatic events (3.2-3.0 Ga, 2.9-2.8 Ga, ~2.5 Ga) and one major metamorphic overprint (~2.5 Ga). The close temporal relationship for different zircon domains reveals that the late-Neoarchean crustal materials were recycled or reworked immediately after their formation, immediately followed by ~2.5 Ga recrystallized metamorphism.The voluminous mantle-derived mafic rocks indicate that the 2.5-2.6 Ga is an important period of crustal addition in the Eastern Hebei region. The peak of Hf model age and the widespread Mesoarchean or Paleoarchean crustal materials in Eastern Hebei may point to another important period of crustal addition before the Neoarchean.