Neoproterozoic basic magmatism in the southeast margin of North China Craton: Evidence from whole-rock geochemistry, U-Pb and Hf isotopic study of zircons from diabase swarms in the Xuzhou-Huaibei area of China
Neoproterozoic basic magmatism in the southeast margin of North China Craton: Evidence from whole-rock geochemistry, U-Pb and Hf isotopic study of zircons from diabase swarms in the Xuzhou-Huaibei area of China
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华北克拉通东南缘新元古代基性岩浆作用——来自徐州—淮北地区辉绿岩群锆石全岩地球化学和U-Pb、Hf同位素研究的证据
DOI：
10.1007/s11430-011-4237-7
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发表时间：
2012-06
期刊：
影响因子：
--
通讯作者：
Xu WenLiang
中科院分区：
文献类型：
--
作者：
Wang QingHai;Yang DeBin;Xu WenLiang
本文对华北陆缘徐淮地区元古宙地层中侵位的闪长岩群进行了锆石U-Pb、Hf合成同位素研究和全岩地球化学研究。闪长岩脉中的锆石在阴极发光（CL）图像中显示出弱的振荡环带，并显示出高的Th/U比值（0.91-6.90），这两种特征都是典型的岩浆成因。SHRIMP和Q-ICP-MS锆石U-Pb定年结果表明，闪长岩群侵位时间约为2000年。890 Ma. Hf同位素分析结果表明，这些锆石的Hf（t）值为2.26 ~ 14.74，Hf模式年龄DM 1和tDM 2分别为843 ~ 1321 Ma和808 ~ 1779 Ma。闪长岩群的地球化学特征是轻稀土元素和大离子亲石元素（Rb、Ba和La）相对富集，Cr和Ni相对富集，而高场强元素（Th、Nb、Ta、Zr和Hf）略有亏损。在构造判别图解上，它们被标绘在板内拉斑玄武岩系列中。综合这些地球化学和同位素资料，推测形成徐淮地区闪长岩墙的原生岩浆可能来源于中元古代的过渡地幔，侵位于大陆边缘拉张背景下。890 Ma.研究结果表明，新元古代（800-900 Ma）岩浆活动不仅限于扬子地块，也发生在华北陆块东南缘。
This paper presents a synthetic U-Pb and Hf isotopic study of zircons and a whole-rock geochemical study on diabase swarms that were emplaced into the Proterozoic formations in the Xuzhou-Huaibei area, the southeast margin of North China Craton. Zircons from the diabase dykes display weak oscillatory zoning in the cathodoluminescence (CL) images and show high Th/U ratios (0.91–6.90), both of which are typical of a magmatic origin. The SHRIMP and Q-ICP-MS U-Pb zircon dating results indicate that the diabase swarms were emplaced at ca. 890 Ma. Hf isotopic analysis on these zircons givesɛHf(t) values ranging from 2.26 to 14.74 and Hf model agetDM1andtDM2ranging from 843 to 1321 Ma and from 808 to 1779 Ma, respectively. Geochemically, the diabase swarms are characterized by a relative enrichment in LREE and LILE (Rb, Ba and La), a comparative enrichment in Cr and Ni, but a slight depletement in HFSE (Th, Nb, Ta, Zr and Hf). They are plotted in the within-plate tholeiite series on the tectonic discrimination diagrams. Taken together, these geochemical and isotopic data suggest that the primary magmas to form the diabase dykes in the Xuzhou-Huaibei area could have been derived from a transitional mantle in the Mesoproterozoic, and were most probably emplaced under a continental margin extensional setting at ca. 890 Ma. The results of this study demonstrate that the Neoproterozoic (800–900 Ma)magmatism was not restricted to the Yangtze Block, but also occurred at the southeast margin of the North China Craton.
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DOI：
10.1111/j.1755-6724.2004.tb00706.x
发表时间：
2004-02
期刊：
Acta Geologica Sinica ‐ English Edition
影响因子：
--
作者：
Shao Ji’an;Zhai Mingguo;Zhang Lüqiao;L. Daming
通讯作者：
Shao Ji’an;Zhai Mingguo;Zhang Lüqiao;L. Daming
影响因子：
3.8
作者：
Songnian Lu;Guochun Zhao;Huichu Wang;Guo Hao
通讯作者：
Songnian Lu;Guochun Zhao;Huichu Wang;Guo Hao
影响因子：
--
作者：
Jin-Hui Yang;Fu-guan Wu;Yanbin Zhang;Q. Zhang;S. Wilde
通讯作者：
Jin-Hui Yang;Fu-guan Wu;Yanbin Zhang;Q. Zhang;S. Wilde
影响因子：
4.9
作者：
Xuan‐Ce Wang;Xian‐Hua Li;Wu-Xian Li;Zheng‐Xiang Li;Y. Liu;Yue-heng Yang;Xi-rong Liang;X. Tu
通讯作者：
Xuan‐Ce Wang;Xian‐Hua Li;Wu-Xian Li;Zheng‐Xiang Li;Y. Liu;Yue-heng Yang;Xi-rong Liang;X. Tu
影响因子：
2.6
作者：
Chuan-Lin Zhang;Zheng‐Xiang Li;Xian‐Hua Li;Haimin Ye;Aiguo Wang;K. Guo
通讯作者：
Chuan-Lin Zhang;Zheng‐Xiang Li;Xian‐Hua Li;Haimin Ye;Aiguo Wang;K. Guo