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
The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been el...The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been elucidated through numerical simulation about the tectonic stress field analysis. Numerical simulation of the tectonic stress field conducted for the major mineralization stage of the Jiujiang-Ruichang junction area reveals that the stress field of the junction structure at the major mineralization stage shows a relatively close relationship with the formation of the ore deposits (occurrences).展开更多
The Linglong-Jiaojia ore-centralized district is controlled by the tectonic stress field characterized by the combination of extension and strike-slip, and the dip, dip angle, pitch and pitch angle of the ore bodies a...The Linglong-Jiaojia ore-centralized district is controlled by the tectonic stress field characterized by the combination of extension and strike-slip, and the dip, dip angle, pitch and pitch angle of the ore bodies are all constrained by the dynamic conditions of the tectonics. The metallotectonic series for the ore-centralized district belong to the type of a combination of extension and strike-slip and can be subdivided into four sub-series. The ore-forming process in the brittle regime can be disintegrated into two stages, i.e., the embryonic fracture stage and the megascopic fracture stage, and ore-forming process is rather common in the ore-centralized district at the former stage. Moreover, several key structural patterns and their features were discussed and a preliminary assessment about the ore-forming prospect in this district was made in the paper.展开更多
The volcanic rocks of the Xiong'er Group occur widely in the southern part of the North China Craton, which mark the beginning of the cover in the southern part of the North China Craton. The age of the volcanic r...The volcanic rocks of the Xiong'er Group occur widely in the southern part of the North China Craton, which mark the beginning of the cover in the southern part of the North China Craton. The age of the volcanic rocks is thus crucial to understand the tectonic regime and evolutionary history of the North China Craton in the Proterozoic age. Zircons from five volcanic rocks and intrusions were dated by U-Pb SHRIMP method. The results indicate that the Xiong'er Group formed in 1.80--1.75 Ga of Paleo-Proterozoic. Since the Xiong'er Group formed earlier than the Changcheng System, the earliest rocks in the Changcheng System is therefore assumed to be formed in 1.75 Ga. A thermal-tectonic event of ca. 1.84 Ga is indicated by new zircon U-Pb SHRIMP ages in the southern part of the North China Craton. The volcanic rocks of the Xiong'er Group thus represent the initial magmatism of the Paleo-Proterozoic breakup of the North China Craton. Numerous inherited zircons in the volcanic rocks mainly formed in ～2.20 Ga, indicating that the source magma of the volcanic rocks may be derived from the ～2.20 Ga crust, or from a mantle magma with significant contamination of the ～2.20 Ga crust.展开更多
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.
文摘The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been elucidated through numerical simulation about the tectonic stress field analysis. Numerical simulation of the tectonic stress field conducted for the major mineralization stage of the Jiujiang-Ruichang junction area reveals that the stress field of the junction structure at the major mineralization stage shows a relatively close relationship with the formation of the ore deposits (occurrences).
基金supported by China National Science Foundation Grant No.40072022CAS Knowledge Innovation Project No.KZCX2-SW-1l7
文摘The Linglong-Jiaojia ore-centralized district is controlled by the tectonic stress field characterized by the combination of extension and strike-slip, and the dip, dip angle, pitch and pitch angle of the ore bodies are all constrained by the dynamic conditions of the tectonics. The metallotectonic series for the ore-centralized district belong to the type of a combination of extension and strike-slip and can be subdivided into four sub-series. The ore-forming process in the brittle regime can be disintegrated into two stages, i.e., the embryonic fracture stage and the megascopic fracture stage, and ore-forming process is rather common in the ore-centralized district at the former stage. Moreover, several key structural patterns and their features were discussed and a preliminary assessment about the ore-forming prospect in this district was made in the paper.
文摘The volcanic rocks of the Xiong'er Group occur widely in the southern part of the North China Craton, which mark the beginning of the cover in the southern part of the North China Craton. The age of the volcanic rocks is thus crucial to understand the tectonic regime and evolutionary history of the North China Craton in the Proterozoic age. Zircons from five volcanic rocks and intrusions were dated by U-Pb SHRIMP method. The results indicate that the Xiong'er Group formed in 1.80--1.75 Ga of Paleo-Proterozoic. Since the Xiong'er Group formed earlier than the Changcheng System, the earliest rocks in the Changcheng System is therefore assumed to be formed in 1.75 Ga. A thermal-tectonic event of ca. 1.84 Ga is indicated by new zircon U-Pb SHRIMP ages in the southern part of the North China Craton. The volcanic rocks of the Xiong'er Group thus represent the initial magmatism of the Paleo-Proterozoic breakup of the North China Craton. Numerous inherited zircons in the volcanic rocks mainly formed in ～2.20 Ga, indicating that the source magma of the volcanic rocks may be derived from the ～2.20 Ga crust, or from a mantle magma with significant contamination of the ～2.20 Ga crust.
