The transportation of magma in sedimentary basins often occurs through extensive dyke-sill networks.The role of sills on the plumbing system in rifted margins and the impact of sills on hydrocarbon reservoirs of prosp...The transportation of magma in sedimentary basins often occurs through extensive dyke-sill networks.The role of sills on the plumbing system in rifted margins and the impact of sills on hydrocarbon reservoirs of prospective sedimentary basins has long been an area of great industrial interest and scientific debate.Based on 2D seismic reflection,we present data on how the sills emplaced to form a magmatic plumbing system of the volcanic system for the Zhongjiannan Basin(ZJNB).The results show that sixty-nine sills and fourteen forced folds have been identified.The distribution and geometry of the sills suggest that magma flowed from west to east and then ascended to near the surface.The onlap relationship of the forced folds indicates that the timing of magmatic activities can be constrained at ca.0.2 Ma.The spatial and temporal occurrences of intrusions imply that the strong post-rift magmatism in ZJNB was associated with the Hainan mantle plume arising from the core-mantle boundary.Furthermore,these forced folds could produce several types of hydrocarbon traps,due to accommodation through bending and uplift of the overlying rock and free surface,but it is critical to evaluate the effect of such emplacement when setting exploration targets.展开更多
Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in t...Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in the continental slope area of the western South China Sea. Based on the interpretation and analysis of multi-beam bathymetry and two-dimensional multi-channel seismic data, the geology of the canyons has however not been studied yet. In this paper, the morphology and distribution characteristics of the canyon are carefully described,the sedimentary filling structure and its evolution process of the canyon are analyzed, and then its controlling factors are discussed. The results show that Rizhao Canyons group is a large slope restricted canyon group composed of one east-west west main and nine branch canyons extending to the south. The canyon was formed from the late Miocene to the Quaternary. The east-west main canyon is located in the transition zone between the northern terrace and the southern Zhongjiannan Slope, and it is mainly formed by the scouring and erosion of the material source from the west, approximately along the slope direction. Its development and evolution is mainly controlled by sediment supply and topographic conditions, the development of 9 branch canyons is mainly controlled by gravity flow and collapse from the east-west main canyon. This understanding result is a supplement to the study of “source-channel–sink” sedimentary system in the west of the South China Sea, and has important guiding significance for the study of marine geological hazards.展开更多
基金supported by the National Key Research and Development Project(2019YFA0708500)the National Natural Science Foundation of China(No.42202170 and U20B6001)。
文摘The transportation of magma in sedimentary basins often occurs through extensive dyke-sill networks.The role of sills on the plumbing system in rifted margins and the impact of sills on hydrocarbon reservoirs of prospective sedimentary basins has long been an area of great industrial interest and scientific debate.Based on 2D seismic reflection,we present data on how the sills emplaced to form a magmatic plumbing system of the volcanic system for the Zhongjiannan Basin(ZJNB).The results show that sixty-nine sills and fourteen forced folds have been identified.The distribution and geometry of the sills suggest that magma flowed from west to east and then ascended to near the surface.The onlap relationship of the forced folds indicates that the timing of magmatic activities can be constrained at ca.0.2 Ma.The spatial and temporal occurrences of intrusions imply that the strong post-rift magmatism in ZJNB was associated with the Hainan mantle plume arising from the core-mantle boundary.Furthermore,these forced folds could produce several types of hydrocarbon traps,due to accommodation through bending and uplift of the overlying rock and free surface,but it is critical to evaluate the effect of such emplacement when setting exploration targets.
基金The Major Special Project of Guangdong Provincial Laboratory of Southern Marine Science and Engineering(Guangzhou) under contract No. GML2019ZD0207the National Natural Science Foundation of China under contract No. U20A20100the China Geological Survey Project under contract Nos DD20221712, DD20221719 and DD20191002。
文摘Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in the continental slope area of the western South China Sea. Based on the interpretation and analysis of multi-beam bathymetry and two-dimensional multi-channel seismic data, the geology of the canyons has however not been studied yet. In this paper, the morphology and distribution characteristics of the canyon are carefully described,the sedimentary filling structure and its evolution process of the canyon are analyzed, and then its controlling factors are discussed. The results show that Rizhao Canyons group is a large slope restricted canyon group composed of one east-west west main and nine branch canyons extending to the south. The canyon was formed from the late Miocene to the Quaternary. The east-west main canyon is located in the transition zone between the northern terrace and the southern Zhongjiannan Slope, and it is mainly formed by the scouring and erosion of the material source from the west, approximately along the slope direction. Its development and evolution is mainly controlled by sediment supply and topographic conditions, the development of 9 branch canyons is mainly controlled by gravity flow and collapse from the east-west main canyon. This understanding result is a supplement to the study of “source-channel–sink” sedimentary system in the west of the South China Sea, and has important guiding significance for the study of marine geological hazards.
