Geochronology, petrogenesis and tectonic implications of Paleoproterozoic granitoid rocks in the Jiaobei Terrane, North China Craton
Geochronology, petrogenesis and tectonic implications of Paleoproterozoic granitoid rocks in the Jiaobei Terrane, North China Craton
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华北克拉通胶北地体古元古代花岗岩年代学、岩石成因及构造意义
DOI：
10.1016/j.precamres.2013.12.004
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发表时间：
2014-12
影响因子：
3.8
通讯作者：
Fang Wang
中科院分区：
文献类型：
--
作者：
Jianhui Liu;Fulai Liu;Zhengjiang Ding;Pinghua Liu;Chunli Guo;Fang Wang
华北克拉通焦北地块古元古代花岗质岩石主要包括变形角闪石/含黑云母二长花岗岩片麻岩、未变形的含黑云母正长花岗岩和含电气石的伟晶质花岗岩。为了确定花岗岩类的侵位年龄、来源和岩石成因，我们对胶北地块3块具有代表性的古元古代花岗岩进行了LA-ICP-MS耦合U-Pb定年、微量元素和原位Hf同位素研究。新的锆石U-Pb数据显示，变形二长花岗岩片麻岩和未变形正长花岗岩的就位年龄分别为2181±12 Ma和1801±21 Ma。焦北地体中变形角闪岩/含黑云母二长花岗岩片麻岩与辽基花岗岩共同定义了约2.2 ~ 2.0 Ga的构造前花岗岩事件，而未变形的正长花岗岩对应约1.8 Ga的构造后或造山带花岗岩事件。构造前含角闪质二长花岗质片麻岩锆石的δ Hf(t)值为−2.13 ~ +6.18（平均= +1.2），两期Hf模式年龄（TDM2）为2313 ~ 2780 Ma，与2.5 Ga左右TTG岩石具有相同的地壳演化趋势，表明其成因为2.5 Ga左右TTG岩石的重熔。构造前含黑云母二长花岗质片麻岩锆石的负Hf(t)值为−7.36 ~−2.85（平均=−5.26），两期Hf模式年龄（TDM2）为2930 ~ 3206 Ma，与2.7 ~ 2.9 Ga TTG岩石的地壳演化趋势相同，表明其演化过程是由2.7 ~ 2.9 Ga TTG岩石部分熔融形成的。构造后同长花岗岩锆石的负Hf(t)值为- 6.58 ~ - 3.26（平均= - 4.89），两阶段Hf模式年龄（TDM2）在2663 ~ 2868 Ma之间，与约2.5 Ga TTG岩石具有相同的地壳演化趋势，表明其成因为约2.5 Ga TTG岩石的部分熔融作用。从胶北地体辽集地区至安徽蚌埠地区2.2 ~ 2.0 Ga的构造前a型变形花岗岩线状带，以及同期的基性侵入岩和双峰型火山组合，表明在2.2 ~ 2.0 Ga时期，胶辽集带发生了广泛的伸展。构造后或造山期花岗岩类事件可能与华北克拉通合并后的伸展有关。
Paleoproterozoic granitoid rocks in the Jiaobei Terrane of the North China Craton mainly comprise deformed hornblende/biotite-bearing monzogranitic gneisses, undeformed biotite-bearing syenogranite, and tourmaline-bearing pegmatitic granite. In order to define the emplacement ages, sources, and petrogenesis of the granitoids, we have conducted a coupled LA-ICP-MS U–Pb dating, trace element and in situ Hf isotopic study of zircons from three representative Paleoproterozoic granitoid rocks in the Jiaobei Terrane. Our new zircon U–Pb data yield emplacement ages of 2181 ± 12 and 1801 ± 21 Ma for deformed monzogranitic gneiss and undeformed syenogranite, respectively. The deformed hornblende/biotite-bearing monzogranitic gneisses in the Jiaobei Terrane, along with the Liaoji granitoids, define pre-tectonic granitoid events at ca. 2.2–2.0 Ga, whereas the undeformed syenogranite corresponds to the post-tectonic or anorogenic granitoid event at ca. 1.8 Ga. Zircons from the pre-tectonic hornblende-bearing monzogranitic gneiss haveɛHf(t)values varying from −2.13 to +6.18 (average = +1.2), two-stage Hf model ages (TDM2) of 2313–2780 Ma and same trends of crustal evolution as ca. 2.5 Ga TTG rocks, suggesting an origin by remelting of ca. 2.5 Ga TTG rocks. Zircons from the pre-tectonic biotite-bearing monzogranitic gneiss have negativeɛHf(t)values of −7.36 to −2.85 (average = −5.26), two-stage Hf model ages (TDM2) of 2930–3206 Ma and the same trends of crustal evolution as ca. 2.7 and/or ca. 2.9 Ga TTG rocks, indicating derivation by partial melting of ca. 2.7 and/or ca. 2.9 Ga TTG rocks. Zircons from the post-tectonic syenogranite display negativeɛHf(t)values ranging from–6.58 to −3.26 (average = −4.89), two-stage Hf model ages (TDM2) varying from 2663 to 2868 Ma, and the same trends of crustal evolution as ca. 2.5 Ga TTG rocks, indicating an origin by partial melting of ca. 2.5 Ga TTG rocks. The linear belt of pre-tectonic, deformed A-type granitoid rocks with emplacement ages of 2.2–2.0 Ga from the Liaoji area, Jiaobei Terrane, through to the Bengbu area of Anhui Province, together with the coeval mafic intrusions and bimodal volcanic assemblages, suggest that widespread extensions occurred along the Jiao-Liao-Ji Belt in the period of 2.2–2.0 Ga. In contrast, the post-tectonic or anorogenic granitoid events may be linked to extensions following the amalgamation of the North China Craton.
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影响因子：
3.8
作者：
Jian‐Bo Zhou;S. Wilde;Guochun Zhao;Changqing Zheng;W. Jin;Xingzhou Zhang;Hongjiang Cheng
通讯作者：
Jian‐Bo Zhou;S. Wilde;Guochun Zhao;Changqing Zheng;W. Jin;Xingzhou Zhang;Hongjiang Cheng
影响因子：
3.1
作者：
Jian Zhang;Guochun Zhao;San-zhong Li;M. Sun;Shuwen Liu;S. Wilde;A. Kröner;C. Yin
通讯作者：
Jian Zhang;Guochun Zhao;San-zhong Li;M. Sun;Shuwen Liu;S. Wilde;A. Kröner;C. Yin
影响因子：
6.1
作者：
Guochun Zhao;M. Zhai
通讯作者：
Guochun Zhao;M. Zhai
影响因子：
1.8
作者：
S. Z. Li;Guochun Zhao;M. Santosh;X. Liu;L. Dai
通讯作者：
S. Z. Li;Guochun Zhao;M. Santosh;X. Liu;L. Dai
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