Complex Precambrian crustal evolution beneath the northeastern Yangtze Craton reflected by zircons from Mesozoic volcanic rocks of the Fanchang basin, Anhui Province
Complex Precambrian crustal evolution beneath the northeastern Yangtze Craton reflected by zircons from Mesozoic volcanic rocks of the Fanchang basin, Anhui Province
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安徽繁昌盆地中生代火山岩锆石反映扬子克拉通东北部复杂前寒武纪地壳演化
DOI：
10.1016/j.precamres.2012.07.005
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发表时间：
2012-11
影响因子：
3.8
通讯作者：
Ren HW
中科院分区：
文献类型：
--
作者：
Tang Huayun;Zheng Jianping;Yu CM;Ren HW
关于扬子江东北部前寒武纪深部地壳的增生改造历史，我们的认识仍然很少。火山岩中的锆石不仅可以提供寄主岩浆中锆石的精确结晶年龄，而且可以提供岩浆上升过程中深地壳岩石的独特历史信息。对安徽繁昌盆地晚中生代中坟村组和科斗山组粗安岩进行了原位U-Pb年龄和Hf同位素分析。锆石具有相对复杂的内部结构。中芬村粗安岩中4个锆石的206 Pb/238 U截距年龄为133.0±3.2Ma，Hf模式年龄为2.8-2.4Ga（T地壳），且δ Hf（t）为负（-25.15 ~-18.72），表明该熔岩形成于早白垩世。壳斗山黑云母粗安岩的锆石206 Pb/238 U年龄为126± 1 Ma，其Hf（t）值为负值，但相对较高（达-4.34），表明其形成时代与白垩纪A型花岗岩和双峰式岩浆活动大致相同。更为重要的是，繁昌火山岩中元古宙锆石捕虏晶的U-Pb年龄和Hf同位素表明，扬子东北部深部地壳可能存在未出露的太古代（如3.4-2.9Ga和2.8-2.5Ga）组分，在本区露头中很少发现，经历了复杂的演化历史，包括3.4-2.9Ga时年轻幔源物质的加入，前寒武纪地壳改造时间分别为2.0-1.8Ga、0.8Ga和133- 126 Ma。扬子江东北部陆壳增生改造的历史可能与扬子江大范围内地壳演化的主要阶段，特别是太古代至古元古代的地壳演化不完全一致。
Our knowledge of the Precambrian accretion and reworking history of deep crust beneath the northeastern Yangtze Craton is still sparse. Zircons from volcanic rocks can not only give accurate crystallization ages for zircons within the host magmas, but also provide unique information on the history of deep crustal rocks sampled during magma ascent. In situ U–Pb ages and Hf-isotopes were analyzed on zircons from two trachyandesites from the Late Mesozoic Zhongfencun and Kedoushan Formations in the Fanchang basin, Anhui Province. The zircons exhibit relatively complex internal structures. Four zircons in the Zhongfencun trachyandesite yield a lower intercept206Pb/238U age of 133.0±3.2Ma, with Hf model ages of 2.8–2.4Ga (Tcrust) and significantly negative ɛHf(t) (−25.15 to −18.72), demonstrating that this lava formed in Early Cretaceous time. Zircons in the Kedoushan biotite trachyandesite yield a206Pb/238U age of 126±1Ma, as well as negative but relatively high ɛHf(t) values (up to −4.34), revealing it formed roughly coeval with the Cretaceous A-type granites and bimodal magmatism in this region. More significantly, U–Pb ages and Hf isotopes for Proterozoic zircon xenocrysts in the Fanchang volcanic rocks reveal that the northeastern Yangtze deep crust probably contains unexposed Archean (e.g. 3.4–2.9Ga and 2.8–2.5Ga) components, rarely identified from the outcrops in this area, and has undergone complex evolutional history, including the addition of juvenile mantle-derived materials at 3.4–2.9Ga, ca 2.65Ga and ca 0.8Ga, and reworking of the Precambrian crust at ca 2.0–1.8Ga, ca 0.8Ga and 133–126Ma. The history of the continental crust's accretion and reworking of the northeastern Yangtze Craton may not fully coincide with the major episodes of crustal evolution in the wider Yangtze Craton, especially during the Archean to Paleoproterozoic periods.
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影响因子：
1.2
作者：
E. Belousova;W. Griffin;S. Shee;S. Jackson;S. O’Reilly
通讯作者：
E. Belousova;W. Griffin;S. Shee;S. Jackson;S. O’Reilly
DOI：
10.1086/341762
发表时间：
2002-09
期刊：
The Journal of Geology
影响因子：
--
作者：
Mei‐Fu Zhou;A. Kennedy;M. Sun;J. Malpas;C. Lesher
通讯作者：
Mei‐Fu Zhou;A. Kennedy;M. Sun;J. Malpas;C. Lesher
DOI：
10.1007/s11430-008-0111-7
发表时间：
2008-10
期刊：
Science in China Series D-Earth Sciences
影响因子：
--
作者：
Lu, San Ming;Yuan, Feng;Shang, Shi Gui;Zhao, Guo Chun;Fan, Yu;Meffre, Sebastien;Zhou, Tao Fa;Cooke, David
通讯作者：
Cooke, David
影响因子：
3.8
作者：
Shao‐Bing Zhang;Yong Zheng;Y. Wu;Zi‐Fu Zhao;Shan Gao;Fu-Yuan Wu
通讯作者：
Shao‐Bing Zhang;Yong Zheng;Y. Wu;Zi‐Fu Zhao;Shan Gao;Fu-Yuan Wu
影响因子：
56.9
作者：
E. Scherer;C. Münker;K. Mezger
通讯作者：
E. Scherer;C. Münker;K. Mezger