The Sulu Orogen preserves the Neoproterozoic tectonic-magmatic events,corresponding to the breaking up of the Rodinia supercontinent.The ages and petrogenesis of meta-igneous rocks in the Liansandao area in the northe...The Sulu Orogen preserves the Neoproterozoic tectonic-magmatic events,corresponding to the breaking up of the Rodinia supercontinent.The ages and petrogenesis of meta-igneous rocks in the Liansandao area in the northern Sulu Orogen are not well-constrained.This study reports zircon U-Pb ages and Hf isotopes of these rocks from the Liansandao area.Three meta-igneous rock samples give similar weighted mean 206 Pb/238 U ages of 744±11,767±12,and 762±15 Ma,respectively,indicating the Neoproterozoic crystallization ages.These rocks formed coevally with the Wulian and Yangkou intrusions that located along the Yantai-Qingdao-Wulian fault zone.The Neoproterozoic ages indicate that the meta-igneous rocks from the Liansandao area have affinity to the Yangtze Block.The three samples haveεHf(t)values of-7.2–-10.5,-6.0–-17.5,and-6.8–-12.0,respectively.These negativeεHf(t)values indicate a primarily crustal source.However,the widely variousεHf(t)values that are higher than the continental crust,suggesting magma mixing between mantle-derived materials and the continental crust or source heterogeneity.Combined with the Hf model ages and geochemical characteristics,the monzodiorite(sample LSD-2)is most likely to be mantle-derived magma then interacted with ancient continental crust,and the granitic protolith(samples LSD-1 and LSD-3)in the Liansandao area might derive from the re-melting of a Paleoproterozoic continental crust at^750 Ma,resulting from the upwelling and underplating of mantle-derived magma formed in an extensional setting due to the break-up of the Rodinia supercontinent.展开更多
The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm Nd isochron age is (782±164)...The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm Nd isochron age is (782±164) Ma. All of these indicate that there was an ancient continental block in the Proterozoic and a rifting occurring on this continental block during ±800 Ma.展开更多
基金financially supported by the Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology (No. MGQNLM201902)the National Natural Science Foundation of China (Nos. 41472155,41876037)+2 种基金the Scientific and Technological Innovation Project of the China Ocean Mineral Resources R & D Association (No. DY135-N2-1-04)the Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents (No. 2016RCJJ008)the SDUST Research Fund (No. 2015TDJH101).
文摘The Sulu Orogen preserves the Neoproterozoic tectonic-magmatic events,corresponding to the breaking up of the Rodinia supercontinent.The ages and petrogenesis of meta-igneous rocks in the Liansandao area in the northern Sulu Orogen are not well-constrained.This study reports zircon U-Pb ages and Hf isotopes of these rocks from the Liansandao area.Three meta-igneous rock samples give similar weighted mean 206 Pb/238 U ages of 744±11,767±12,and 762±15 Ma,respectively,indicating the Neoproterozoic crystallization ages.These rocks formed coevally with the Wulian and Yangkou intrusions that located along the Yantai-Qingdao-Wulian fault zone.The Neoproterozoic ages indicate that the meta-igneous rocks from the Liansandao area have affinity to the Yangtze Block.The three samples haveεHf(t)values of-7.2–-10.5,-6.0–-17.5,and-6.8–-12.0,respectively.These negativeεHf(t)values indicate a primarily crustal source.However,the widely variousεHf(t)values that are higher than the continental crust,suggesting magma mixing between mantle-derived materials and the continental crust or source heterogeneity.Combined with the Hf model ages and geochemical characteristics,the monzodiorite(sample LSD-2)is most likely to be mantle-derived magma then interacted with ancient continental crust,and the granitic protolith(samples LSD-1 and LSD-3)in the Liansandao area might derive from the re-melting of a Paleoproterozoic continental crust at^750 Ma,resulting from the upwelling and underplating of mantle-derived magma formed in an extensional setting due to the break-up of the Rodinia supercontinent.
文摘The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm Nd isochron age is (782±164) Ma. All of these indicate that there was an ancient continental block in the Proterozoic and a rifting occurring on this continental block during ±800 Ma.
