SHRIMP zircon U-Pb ages for the Paleoproterozoic metamorphic-magmatic events in the southeast margin of the North China Craton  

作　　者：GUO SuShu LI ShuGuang 

机构地区：[1]CAS Key Laboratory of Crust-Mantle Materials and Environments,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China Earth Sciences》2009年第8期1039-1045,共7页中国科学（地球科学英文版）

基　　金：Supported by National Natural Science Foundation of China (Grant No. 40634023)

摘　　要：A garnet-pyroxene bearing amphibolite as a xenolith hosted by the Mesozoic igneous rocks from Xuzhou-Suzhou area was dated by zircon SHRIMP U-Pb method, which yields a metamorphic age of 1918 ± 56 Ma. In addition, the zircons from a garnet amphibolite as a lens interbedded with marble in the Archean metamorphic complex named Wuhe group in the Bengbu uplift give a metamorphic U-Pb age of 1857 ± 19 Ma, and the zircons from Shimenshan deformed granite in the eastern margin of the Bengbu uplift give a magma crystallization U-Pb age of 2054 ± 22 Ma. Both the Xuzhou-Suzhou area and Bengbu uplift are located in the southeastern margin of the North China Craton. Therefore,these ages indicate that there is a Paleoproterozoic tectonic zone in the southeastern margin of the North China Craton, and its metamorphic and magmatic ages are consistent with those of the other three Paleoproterozoic tectonic zones in the North China Craton. In view of the large scale sinistral strike-slip movement occurred at the Mesozoic along the Tan-Lu fault zone, the position of the eastern Shandong area, which is a south section of the Paleoproterozoic Jiao-Liao-Ji Belt, was correlated to Xuzhou-Suzhou-Bengbu area prior to movement of the Tan-Lu fault zone. This suggests that the Xuzhou-Suzhou-Bengbu Paleoproterozoic tectonic zone might be a southwest extension of the Paleoproterozoic Jiao-Liao-Ji Belt.A garnet-pyroxene bearing amphibolite as a xenolith hosted by the Mesozoic igneous rocks from Xuzhou-Suzhou area was dated by zircon SHRIMP U-Pb method, which yields a metamorphic age of 1918 ± 56 Ma. In addition, the zircons from a garnet amphibolite as a lens interbedded with marble in the Archean metamorphic complex named Wuhe group in the Bengbu uplift give a metamorphic U-Pb age of 1857 ± 19 Ma, and the zircons from Shimenshan deformed granite in the eastern margin of the Bengbu uplift give a magma crystallization U-Pb age of 2054 ± 22 Ma. Both the Xuzhou-Suzhou area and Bengbu uplift are located in the southeastern margin of the North China Craton. Therefore, these ages indicate that there is a Paleoproterozoic tectonic zone in the southeastern margin of the North China Craton, and its metamorphic and magmatic ages are consistent with those of the other three Paleoproterozoic tectonic zones in the North China Craton. In view of the large scale sinistral strike-slip movement occurred at the Mesozoic along the Tan-Lu fault zone, the position of the eastern Shandong area, which is a south section of the Paleoproterozoic Jiao-Liao-Ji Belt, was correlated to Xuzhou-Suzhou-Bengbu area prior to movement of the Tan-Lu fault zone. This suggests that the Xuzhou-Suzhou-Bengbu Paleoproterozoic tectonic zone might be a southwest extension of the Paleoproterozoic Jiao-Liao-Ji Belt.

关 键 词：SHRIMP U-PB DATING the North China CRATON PALEOPROTEROZOIC 

分 类 号：P597.3[天文地球—地球化学]