The late Paleozoic tectonic framework of the southeastern Central Asian Orogenic Belt is key to restricting the accretion orogeny between the Siberia Craton and the North China Craton. To clarify the framework, petrog...The late Paleozoic tectonic framework of the southeastern Central Asian Orogenic Belt is key to restricting the accretion orogeny between the Siberia Craton and the North China Craton. To clarify the framework, petrogenesis of early Permian intrusive rocks from southeastern Inner Mongolia was studied. Zircon U-Pb dating for bojite and syenogranite from Ar-Horqin indicate that they were emplaced at 288–285 Ma. Geochemical data reveal that the bojite is highly magnesian and low-K to middle-K calc-alkaline, with E-MORB-type REE and IAB-like trace element patterns. The syenogranite is a middle-K calc-alkaline fractionated A-type granite and shows oceanic-arc-like trace element patterns, with depleted Sr-Nd-Hf isotopes,(~(87)Sr/~(86)Sr)I = 0.7032–0.7042, ε_(Nd)(t) = +4.0 to +6.6 and zircon ε_(Hf)(t) = +11.14 to +14.99. This suggests that the bojite was derived from lithospheric mantle metasomatized by subducted slab melt, while the syenogranite originated from very juvenile arc-related lower crust. Usng data from coeval magmatic rocks from Linxi-Ar-Horqin, the Ar-Horqin intra-oceanic arc was reconstructed, i.e., initial transition in 290–280 Ma and mature after 278 Ma. Combined with regional geological and geophysical materials in southeastern Inner Mongolia, an early Permian tectonic framework as ‘one narrow ocean basin of the PAO', ‘two continental marginal arcs on its northern and southern' and ‘one intra-oceanic arc in its southern' is proposed.展开更多
Objective Petrified wood,as an important component of plant fossils,plays a significant role in understanding the floral composition and terrestrial palaeoclimates of the geological past.Though abundant petrified wood...Objective Petrified wood,as an important component of plant fossils,plays a significant role in understanding the floral composition and terrestrial palaeoclimates of the geological past.Though abundant petrified woods have been found from the Mesozoic deposits in the Great Xing’an Range,NE China,it was rare for systematic investigations to be carried out for these fossil wood remains.展开更多
利用行星式球磨机和超音速火焰喷涂设备制备了6组Ni Cr含量分别为25%、40%、55%、70%、85%和100%的Cr_(3)C_(2)-k Ni Cr涂层,采用冲蚀磨损试验系统测试了各涂层在低、中、高冲击角度下的冲蚀率,并观察了涂层表面的冲蚀磨损特征。采用纳...利用行星式球磨机和超音速火焰喷涂设备制备了6组Ni Cr含量分别为25%、40%、55%、70%、85%和100%的Cr_(3)C_(2)-k Ni Cr涂层,采用冲蚀磨损试验系统测试了各涂层在低、中、高冲击角度下的冲蚀率,并观察了涂层表面的冲蚀磨损特征。采用纳米压痕测试仪、断裂韧性测试仪和维氏硬度仪等设备测试了6组涂层的弹性模量、断裂韧性和维氏硬度。测试分析了涂层的截面形貌和孔隙率,分析了粉末的微观形貌、粒度和成分。结果表明,各涂层内、层间和界面质量好,孔隙率低至0.46%以下;各粉末球形度好、粒度分布均匀性和一致性好、元素分布均匀;随着Ni Cr含量增大,各涂层的显微硬度和弹性模量稳定减小,断裂韧性稳定增大;随着Ni Cr含量的增加,Cr_(3)C_(2)-k Ni Cr涂层的冲蚀磨损行为及特征由典型脆性材料逐渐转为典型塑性材料,低冲击角度下抗冲蚀性能逐渐劣化,而高冲击角度下逐渐增强;低、高冲击角度下抗冲蚀磨损的机制分别是高硬度抵抗冲蚀粒子的切入和高韧性通过塑性变形吸收法向冲击能量。因此,可通过调控Cr_(3)C_(2)-k Ni Cr涂层中Ni Cr含量来适用不同冲击角度下金属陶瓷涂层的抗冲蚀性能需求。展开更多
基金funded by project grants from the Chinese Geological Survey (Grants Nos. DD20190039, DD20160048–01, DD20160345–17, DD20190372, DD20190360 and 1212011220435)the Liaoning Education Department (Grant No. LQN201915)。
文摘The late Paleozoic tectonic framework of the southeastern Central Asian Orogenic Belt is key to restricting the accretion orogeny between the Siberia Craton and the North China Craton. To clarify the framework, petrogenesis of early Permian intrusive rocks from southeastern Inner Mongolia was studied. Zircon U-Pb dating for bojite and syenogranite from Ar-Horqin indicate that they were emplaced at 288–285 Ma. Geochemical data reveal that the bojite is highly magnesian and low-K to middle-K calc-alkaline, with E-MORB-type REE and IAB-like trace element patterns. The syenogranite is a middle-K calc-alkaline fractionated A-type granite and shows oceanic-arc-like trace element patterns, with depleted Sr-Nd-Hf isotopes,(~(87)Sr/~(86)Sr)I = 0.7032–0.7042, ε_(Nd)(t) = +4.0 to +6.6 and zircon ε_(Hf)(t) = +11.14 to +14.99. This suggests that the bojite was derived from lithospheric mantle metasomatized by subducted slab melt, while the syenogranite originated from very juvenile arc-related lower crust. Usng data from coeval magmatic rocks from Linxi-Ar-Horqin, the Ar-Horqin intra-oceanic arc was reconstructed, i.e., initial transition in 290–280 Ma and mature after 278 Ma. Combined with regional geological and geophysical materials in southeastern Inner Mongolia, an early Permian tectonic framework as ‘one narrow ocean basin of the PAO', ‘two continental marginal arcs on its northern and southern' and ‘one intra-oceanic arc in its southern' is proposed.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.41702032 and 41972022)the Liaoning Revitalization of Talents Program(Grant No.XLYC1907037)the Geological Survey Programs of the Chinese Geological Survey(Grant Nos.DD20160048-4 and DD20190039-06)。
文摘Objective Petrified wood,as an important component of plant fossils,plays a significant role in understanding the floral composition and terrestrial palaeoclimates of the geological past.Though abundant petrified woods have been found from the Mesozoic deposits in the Great Xing’an Range,NE China,it was rare for systematic investigations to be carried out for these fossil wood remains.
文摘利用行星式球磨机和超音速火焰喷涂设备制备了6组Ni Cr含量分别为25%、40%、55%、70%、85%和100%的Cr_(3)C_(2)-k Ni Cr涂层,采用冲蚀磨损试验系统测试了各涂层在低、中、高冲击角度下的冲蚀率,并观察了涂层表面的冲蚀磨损特征。采用纳米压痕测试仪、断裂韧性测试仪和维氏硬度仪等设备测试了6组涂层的弹性模量、断裂韧性和维氏硬度。测试分析了涂层的截面形貌和孔隙率,分析了粉末的微观形貌、粒度和成分。结果表明,各涂层内、层间和界面质量好,孔隙率低至0.46%以下;各粉末球形度好、粒度分布均匀性和一致性好、元素分布均匀;随着Ni Cr含量增大,各涂层的显微硬度和弹性模量稳定减小,断裂韧性稳定增大;随着Ni Cr含量的增加,Cr_(3)C_(2)-k Ni Cr涂层的冲蚀磨损行为及特征由典型脆性材料逐渐转为典型塑性材料,低冲击角度下抗冲蚀性能逐渐劣化,而高冲击角度下逐渐增强;低、高冲击角度下抗冲蚀磨损的机制分别是高硬度抵抗冲蚀粒子的切入和高韧性通过塑性变形吸收法向冲击能量。因此,可通过调控Cr_(3)C_(2)-k Ni Cr涂层中Ni Cr含量来适用不同冲击角度下金属陶瓷涂层的抗冲蚀性能需求。
