The South Yellow Sea Basin is partially surrounded by the East Asian continental Meso- Cenozoic widespread igneous rocks belt. Magnetic anomaly and multi-channel seismic data both reveal the prevalent occurrence of ig...The South Yellow Sea Basin is partially surrounded by the East Asian continental Meso- Cenozoic widespread igneous rocks belt. Magnetic anomaly and multi-channel seismic data both reveal the prevalent occurrence of igneous rocks. We preliminarily defined the coupling relation between magnetic anomalies and igneous rock bodies. Some igneous complexes were also recognized by using multi-channel seismic and drilling data. We identified various intrusive and extrusive igneous rock bodies, such as stocks, sills, dikes, laccoliths and volcanic edifice relics through seismic facies analysis. We also forecasted the distribution characteristics of igneous complexes. More than fifty hypabyssal intrusions and volcanic relics were delineated based on the interpretation of magnetic anomaly and dense intersecting multi-channel seismic data. It is an important supplement to regional geology and basin evolution research. Spatial matching relations between igneous rock belts and fractures document that extensional N-E and N-NE-trending deep fractures may be effective pathways for magma intrusion. These fractures formed under the influence of regional extension during the Meso- Cenozoic after the Indosinian movement. Isotopic ages and crosscutting relations between igneous rock bodies and the surrounding bedded sedimentary strata both indicate that igneous activities might have initiated during the Late Jurassic, peaked in the Early Cretaceous, gradually weakened in the Late Cretaceous, and continued until the Miocene. Combined with previous studies, it is considered that the Meso-Cenozoic igneous activities, especially the intensive igneous activity of the Early Cretaceous, are closely associated with the subduction of the Paleo-Pacific Plate.展开更多
As a potential oil and gas reservoir, reef complexes have been a research focus from petroleum geologists for a long time. There are favorable conditions for the development of reef complexes in the South China Sea; h...As a potential oil and gas reservoir, reef complexes have been a research focus from petroleum geologists for a long time. There are favorable conditions for the development of reef complexes in the South China Sea; however, their internal structures, evolution and distribution are still poorly understood. Based on 2D and 3D seismic data, the internal structures and evolution patterns of the reef complexes on the carbonate platform margin in the deep water areas over the western South China Sea were studied in detail. The result shows that two types of reef complexes, i.e., fault controlling platform margin reef complexes and ramp reef complexes have been developed in the study area. The reef complexes have independent or continuous mound or lenticular seismic reflections, with three internal structures （i.e., aggrading, prograding and retrograding structures）. There are different growth rates during the evolution of the reef complexes, resulting in the formation of catch-up reefs, keep-up reefs and quick step reefs. The study also reveals that different platform margin reef complexes have different internal structures and distributions, because of the different platform types. These results may be applied to the exploration and prediction of carbonate platform margin reef complexes in other areas that are similar to the study area.展开更多
The formation of anorthosites in layered intrusions has remained one of petrology＇s most enduring enigmas. We have studied a sequence of layered chromitite, pyroxenite, norite and anorthosite overlying the UG2 chromi...The formation of anorthosites in layered intrusions has remained one of petrology＇s most enduring enigmas. We have studied a sequence of layered chromitite, pyroxenite, norite and anorthosite overlying the UG2 chromitite in the Upper Critical Zone of the eastern Bushveld Complex at the Smokey Hills platinum mine. Layers show very strong medium to large scale lateral continuity, but abundant small scale irregularities and transgressive relationships. Particularly notable are irregular masses and seams of anorthosite that have intrusive relationships to their host rocks. An anorthosite layer locally transgresses several 10 s of metres into its footwall, forming what is referred to as a ＂pothole＂ in the Bushveld Complex. It is proposed that the anorthosites formed from plagioclase-rich crystal mushes that originally accumulated at or near the top of the cumulate pile. The slurries were mobilised during tectonism induced by chamber subsidence, a model that bears some similarity to that generally proposed for oceanic mass flows. The anorthosite slurries locally collapsed into pull-apart structures and injected their host rocks. The final step was down-dip drainage of Fe-rich intercumulus liquid, leaving behind anorthosite adcumulates.展开更多
Shishuoxinyu is a collection of anecdotal stories about the words and deeds of Wei and Jin characters. In this paper, we build a complex network with characters in Shishuoxinyu to analyze the scholarly connections in ...Shishuoxinyu is a collection of anecdotal stories about the words and deeds of Wei and Jin characters. In this paper, we build a complex network with characters in Shishuoxinyu to analyze the scholarly connections in the Wei-Jin and North-South dynasties. The ER random graph, WS small-world network, BA scale-free network, and experimental network are constructed for comparison. The network properties of the experimental network were analyzed using the average degree, average clustering coefficient, and average path length. Degree centrality, mesoscopic centrality, and proximity centrality were selected to understand the importance of the experimental network nodes, and it was found that the king guide had the highest importance in the whole experimental network. Then, through the observation of network degree distribution, this experimental network is considered as a scale-free network with robustness and vulnerability, which is in line with the political characteristics of the Wei-Jin and Northern Dynasties. Finally, ten larger-scale Shi clans are selected to construct a new network for inter-clan linkage analysis. This study helps to uncover the reasons for the rise and fall of the Shi clans during the Wei-Jin and North-South dynasties.展开更多
基金financially supported by The National Special Project for Marine Geology(DD20160147)the National Basic Research Program of China(973 program+1 种基金 Grant No.2013CB429701)the National Natural Science Foundation of China(Grant No.41210005)
文摘The South Yellow Sea Basin is partially surrounded by the East Asian continental Meso- Cenozoic widespread igneous rocks belt. Magnetic anomaly and multi-channel seismic data both reveal the prevalent occurrence of igneous rocks. We preliminarily defined the coupling relation between magnetic anomalies and igneous rock bodies. Some igneous complexes were also recognized by using multi-channel seismic and drilling data. We identified various intrusive and extrusive igneous rock bodies, such as stocks, sills, dikes, laccoliths and volcanic edifice relics through seismic facies analysis. We also forecasted the distribution characteristics of igneous complexes. More than fifty hypabyssal intrusions and volcanic relics were delineated based on the interpretation of magnetic anomaly and dense intersecting multi-channel seismic data. It is an important supplement to regional geology and basin evolution research. Spatial matching relations between igneous rock belts and fractures document that extensional N-E and N-NE-trending deep fractures may be effective pathways for magma intrusion. These fractures formed under the influence of regional extension during the Meso- Cenozoic after the Indosinian movement. Isotopic ages and crosscutting relations between igneous rock bodies and the surrounding bedded sedimentary strata both indicate that igneous activities might have initiated during the Late Jurassic, peaked in the Early Cretaceous, gradually weakened in the Late Cretaceous, and continued until the Miocene. Combined with previous studies, it is considered that the Meso-Cenozoic igneous activities, especially the intensive igneous activity of the Early Cretaceous, are closely associated with the subduction of the Paleo-Pacific Plate.
基金The National Science and Technology Major Project of China under contract No.2011ZX05025-002-02the National Natural Science Foundation of China under contract No.41202086+3 种基金the National Natural Science Foundation of China under contract No.41102068China Postdoctoral Science Special Fund under contract No.201003654the Special Fund for Basic Scientific Research of Central Colleges,China University of Geosciences(Wuhan)under contract No.CUGL100252the Young Scholars Development Fund of SWPU under contract No.201599010078
文摘As a potential oil and gas reservoir, reef complexes have been a research focus from petroleum geologists for a long time. There are favorable conditions for the development of reef complexes in the South China Sea; however, their internal structures, evolution and distribution are still poorly understood. Based on 2D and 3D seismic data, the internal structures and evolution patterns of the reef complexes on the carbonate platform margin in the deep water areas over the western South China Sea were studied in detail. The result shows that two types of reef complexes, i.e., fault controlling platform margin reef complexes and ramp reef complexes have been developed in the study area. The reef complexes have independent or continuous mound or lenticular seismic reflections, with three internal structures （i.e., aggrading, prograding and retrograding structures）. There are different growth rates during the evolution of the reef complexes, resulting in the formation of catch-up reefs, keep-up reefs and quick step reefs. The study also reveals that different platform margin reef complexes have different internal structures and distributions, because of the different platform types. These results may be applied to the exploration and prediction of carbonate platform margin reef complexes in other areas that are similar to the study area.
文摘The formation of anorthosites in layered intrusions has remained one of petrology＇s most enduring enigmas. We have studied a sequence of layered chromitite, pyroxenite, norite and anorthosite overlying the UG2 chromitite in the Upper Critical Zone of the eastern Bushveld Complex at the Smokey Hills platinum mine. Layers show very strong medium to large scale lateral continuity, but abundant small scale irregularities and transgressive relationships. Particularly notable are irregular masses and seams of anorthosite that have intrusive relationships to their host rocks. An anorthosite layer locally transgresses several 10 s of metres into its footwall, forming what is referred to as a ＂pothole＂ in the Bushveld Complex. It is proposed that the anorthosites formed from plagioclase-rich crystal mushes that originally accumulated at or near the top of the cumulate pile. The slurries were mobilised during tectonism induced by chamber subsidence, a model that bears some similarity to that generally proposed for oceanic mass flows. The anorthosite slurries locally collapsed into pull-apart structures and injected their host rocks. The final step was down-dip drainage of Fe-rich intercumulus liquid, leaving behind anorthosite adcumulates.
文摘Shishuoxinyu is a collection of anecdotal stories about the words and deeds of Wei and Jin characters. In this paper, we build a complex network with characters in Shishuoxinyu to analyze the scholarly connections in the Wei-Jin and North-South dynasties. The ER random graph, WS small-world network, BA scale-free network, and experimental network are constructed for comparison. The network properties of the experimental network were analyzed using the average degree, average clustering coefficient, and average path length. Degree centrality, mesoscopic centrality, and proximity centrality were selected to understand the importance of the experimental network nodes, and it was found that the king guide had the highest importance in the whole experimental network. Then, through the observation of network degree distribution, this experimental network is considered as a scale-free network with robustness and vulnerability, which is in line with the political characteristics of the Wei-Jin and Northern Dynasties. Finally, ten larger-scale Shi clans are selected to construct a new network for inter-clan linkage analysis. This study helps to uncover the reasons for the rise and fall of the Shi clans during the Wei-Jin and North-South dynasties.
