A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are ...A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are rich in Fe, Mg, K and P and such incompatible elements as Rb, Ba, U and Sr and REE; theinitial ^(87)Sr / ^(86)Sr ratios range from 0.7055 to 0.7057. They might have originated in the altered upper mantle.On that basis coupled with the distribution of the Triassic System and the tectonic deformation, it is suggestedthat there should have existed a tectono-magmatic belt in the area in Triassic time, which is an important mani-festation of the Indosinian movement in the area.展开更多
The metasedimentary Lujiapuzi Formation crops out along the northeastern margin of the North China Craton, close to the Yan-Liao Rift. The age and tectonic setting of the formation, and its relationship with the Yan-L...The metasedimentary Lujiapuzi Formation crops out along the northeastern margin of the North China Craton, close to the Yan-Liao Rift. The age and tectonic setting of the formation, and its relationship with the Yan-Liao Rift are currently unclear. Here we present detrital zircon U-Pb ages, and Hf isotopic and geochemical data for the Lujiapuzi Formation to constrain the timing of deposition, the provenance of the formation, and the regional stratigraphy relationship. Zircon U-Pb dating constrains the timing of deposition of the Lujiapuzi Formation to younger than 1780 Ma, and indicates that most grains were sourced from the Longgang Block and the Paleoproterozoic Liao-Ji Belt. Detailed field investigations and a correlation of the regional stratigraphy reveal that much of the Lujiapuzi Formation is equivalent to the Tuanshanzi Formation in the Yan-Liao Rift; the lower section may represent the earliest sediments deposited within the Fanhe Basin. Based on these results and the findings of previous studies, we suggest that the base of the Changcheng System has an age of 1.80 Ga. Zircon Hf isotopic data indicate that the main period of crustal growth along the northeastern margin of the North China Craton occurred at 3.2–2.5 Ga, with a peak at 2.9–2.7 Ga.展开更多
Combining the single-grain low-temperature apatite fission track with high-temperature zircon U-Pb dating of sandstone can better reveal the temporal association between the source and depositional site, and identify ...Combining the single-grain low-temperature apatite fission track with high-temperature zircon U-Pb dating of sandstone can better reveal the temporal association between the source and depositional site, and identify both the age component of the source terrain and subsequent thermo-tectonic events after deposition. This paper introduces the single- grain zircon U-Pb dating and fission track (FT) dating of sediments from the Beipiao basin in Northeast China. The U-Pb ages of 18 single zircon grains collected from the early Jurassic Beipiao Formation range from 194.3±2.9 to 233.8±4.2 Ma and most of apatite FT ages are about 30-40 Ma, indicating that the eastern part of the Yan-Liao orogenic belt experienced an obvious tectonic seesawing during Meso-Cenozoic time. The eastern part of Liaoning Province (the Liaodong block) uplifted in the early Mesozoic (230-190 Ma) and formed a geological landscape of high mountains, while the western part of the province (the Liaoxi area) subsided relatively and thousand-meter-scale sediments were deposited. During the Cenozoic (30-40 Ma), the Liaoxi area uplifted as a whole, and the Xialiaohe Basin sank intensively. The topographic landscape had a great change: high mountains in the west and east of Liaoning Province and low plains in the central area.展开更多
文摘A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are rich in Fe, Mg, K and P and such incompatible elements as Rb, Ba, U and Sr and REE; theinitial ^(87)Sr / ^(86)Sr ratios range from 0.7055 to 0.7057. They might have originated in the altered upper mantle.On that basis coupled with the distribution of the Triassic System and the tectonic deformation, it is suggestedthat there should have existed a tectono-magmatic belt in the area in Triassic time, which is an important mani-festation of the Indosinian movement in the area.
基金financially supported by the Nature Science Foundation of China (41772214 and 41872203)the 12th Chinese 1000 Young Talents Program, National Nature Science Foundation of China (2016-67, 32020002)+1 种基金the China Postdoctoral Science Foundation Grant (2018M633210)the China Geological Survey (12120113057900)
文摘The metasedimentary Lujiapuzi Formation crops out along the northeastern margin of the North China Craton, close to the Yan-Liao Rift. The age and tectonic setting of the formation, and its relationship with the Yan-Liao Rift are currently unclear. Here we present detrital zircon U-Pb ages, and Hf isotopic and geochemical data for the Lujiapuzi Formation to constrain the timing of deposition, the provenance of the formation, and the regional stratigraphy relationship. Zircon U-Pb dating constrains the timing of deposition of the Lujiapuzi Formation to younger than 1780 Ma, and indicates that most grains were sourced from the Longgang Block and the Paleoproterozoic Liao-Ji Belt. Detailed field investigations and a correlation of the regional stratigraphy reveal that much of the Lujiapuzi Formation is equivalent to the Tuanshanzi Formation in the Yan-Liao Rift; the lower section may represent the earliest sediments deposited within the Fanhe Basin. Based on these results and the findings of previous studies, we suggest that the base of the Changcheng System has an age of 1.80 Ga. Zircon Hf isotopic data indicate that the main period of crustal growth along the northeastern margin of the North China Craton occurred at 3.2–2.5 Ga, with a peak at 2.9–2.7 Ga.
基金the National Natural Science Foundation of China(No.40306010)Chinese Academy of Sciences(No.KZCX2-SW-117).
文摘Combining the single-grain low-temperature apatite fission track with high-temperature zircon U-Pb dating of sandstone can better reveal the temporal association between the source and depositional site, and identify both the age component of the source terrain and subsequent thermo-tectonic events after deposition. This paper introduces the single- grain zircon U-Pb dating and fission track (FT) dating of sediments from the Beipiao basin in Northeast China. The U-Pb ages of 18 single zircon grains collected from the early Jurassic Beipiao Formation range from 194.3±2.9 to 233.8±4.2 Ma and most of apatite FT ages are about 30-40 Ma, indicating that the eastern part of the Yan-Liao orogenic belt experienced an obvious tectonic seesawing during Meso-Cenozoic time. The eastern part of Liaoning Province (the Liaodong block) uplifted in the early Mesozoic (230-190 Ma) and formed a geological landscape of high mountains, while the western part of the province (the Liaoxi area) subsided relatively and thousand-meter-scale sediments were deposited. During the Cenozoic (30-40 Ma), the Liaoxi area uplifted as a whole, and the Xialiaohe Basin sank intensively. The topographic landscape had a great change: high mountains in the west and east of Liaoning Province and low plains in the central area.
