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
In the present study,Paleozoic Variscan orogenesis was a model of the oroclinal flexion accompanied by extensive magmatism,which could be divided into the following two types:post-tectonic and syn-tectonic tonalite gr...In the present study,Paleozoic Variscan orogenesis was a model of the oroclinal flexion accompanied by extensive magmatism,which could be divided into the following two types:post-tectonic and syn-tectonic tonalite granite,and leuco-granite which were controlled by the tectonic characteristics of the intrusions.It was observed that a very high majority of the samples had displayed discontinuities in their structures,that were later utilized to define the granitoid morphology and development characteristics of the rock during the intrusion phases.Furthermore,it was determined that the tectonics associated with the Alpine orogeny results in the new generation of faults and fractures during the Paleogene Period had produced the development of the Sierras.Due to different weathering processes,the depressions which had resulted in the present granitoid reliefs were found to be exclusively related to the structural development processes during the geological history(either tectonic or magmatic)of the granite,and not as normally interpreted.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.
基金financially supported by the National Natural Science Foundation of China (NSFC) (Nos. 41472155, 41876037)the Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology (No. MGQNLM201902)the Scientific and Technological Innovation Project from the China Ocean Mineral Resources R & D Association (No. DY135-N2-1-04)。
文摘In the present study,Paleozoic Variscan orogenesis was a model of the oroclinal flexion accompanied by extensive magmatism,which could be divided into the following two types:post-tectonic and syn-tectonic tonalite granite,and leuco-granite which were controlled by the tectonic characteristics of the intrusions.It was observed that a very high majority of the samples had displayed discontinuities in their structures,that were later utilized to define the granitoid morphology and development characteristics of the rock during the intrusion phases.Furthermore,it was determined that the tectonics associated with the Alpine orogeny results in the new generation of faults and fractures during the Paleogene Period had produced the development of the Sierras.Due to different weathering processes,the depressions which had resulted in the present granitoid reliefs were found to be exclusively related to the structural development processes during the geological history(either tectonic or magmatic)of the granite,and not as normally interpreted.
