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
Objective Large igneous provinces （LIPs） are sites of spatially contiguous, rapidly emplaced magmatic rocks, which represent the physical and chemical transfer of material from the mantle to the crust. Exposed with...Objective Large igneous provinces （LIPs） are sites of spatially contiguous, rapidly emplaced magmatic rocks, which represent the physical and chemical transfer of material from the mantle to the crust. Exposed within some continental LIPs are felsic and rnafic plutonic and volcanic rocks. Although their volumes are minor compared to the flood basalts, the plutonic rocks of continental LIPs are often associated with economic deposits of precious metals. Within the Permian Tarim LIP of NW China, there are at least two layered ultramafic-mafic intrusions （e.g. Wajilitag and Piqiang） contain economically important Fe- Ti-V oxide deposits. Spatially associated with these layered ultramafic-mafic intrusions are syenitic and granitic plutons, which have chemical characteristics of A- type granitoids.展开更多
The Nagar Parkar complex consists of Neoproterozoic igneous and metamorphic rocks dissected by episodic mafic and felsic dykes.The latter can be classified broadly into porphyritic felsic dykes and aplitic felsic dyke...The Nagar Parkar complex consists of Neoproterozoic igneous and metamorphic rocks dissected by episodic mafic and felsic dykes.The latter can be classified broadly into porphyritic felsic dykes and aplitic felsic dykes(minor)展开更多
The Yilgarn Craton in Western Australia contains evidence of the oldest crust on Earth.Greenstone successions developed after c.3000 Ma show a complex history of juvenile crust generation and crustal reworking.There a...The Yilgarn Craton in Western Australia contains evidence of the oldest crust on Earth.Greenstone successions developed after c.3000 Ma show a complex history of juvenile crust generation and crustal reworking.There are at least three periods of greenstonerelated magmatism in the Yilgarn Craton.The earliest recognised greenstone development consists of volcanic and sedimentary successions deposited between c.3000–2900 Ma.A mantle plume at c.2800 Ma produced large mafic–ultramafic igneous complexes and probably initiated rifting on the eastern side of the craton and incipient rifting in the NW.A second major plume,at c.2700 Ma,was focussed along the rupture created by the c.2800 Ma event and may have been associated with the re-accretion of lithospheric blocks created by the earlier event.Komatiites generated by the c.2700 Ma plume contain world-class Ni deposits,and structures developed subsequent to the peak of plume activity host world-class Au deposits.Recent studies of Ni and Au deposits in the Eastern Goldfields Superterrane have shown how features ranging in scale from the lithosphere to regional structural and stratigraphic controls to local volcanological and sedimentological variations can affect the size and distribution of deposits.This understanding is now being applied in exploration targeting.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financially supported by the National Natural Science Foundation of China (Grant No.41703030)research grants from the East China University of Technology (Grants No.DHBK2015323 and RGET1504)the Jiangxi Provincial Department of Education (Grant No.GJJ150556)
文摘Objective Large igneous provinces （LIPs） are sites of spatially contiguous, rapidly emplaced magmatic rocks, which represent the physical and chemical transfer of material from the mantle to the crust. Exposed within some continental LIPs are felsic and rnafic plutonic and volcanic rocks. Although their volumes are minor compared to the flood basalts, the plutonic rocks of continental LIPs are often associated with economic deposits of precious metals. Within the Permian Tarim LIP of NW China, there are at least two layered ultramafic-mafic intrusions （e.g. Wajilitag and Piqiang） contain economically important Fe- Ti-V oxide deposits. Spatially associated with these layered ultramafic-mafic intrusions are syenitic and granitic plutons, which have chemical characteristics of A- type granitoids.
文摘The Nagar Parkar complex consists of Neoproterozoic igneous and metamorphic rocks dissected by episodic mafic and felsic dykes.The latter can be classified broadly into porphyritic felsic dykes and aplitic felsic dykes(minor)
文摘The Yilgarn Craton in Western Australia contains evidence of the oldest crust on Earth.Greenstone successions developed after c.3000 Ma show a complex history of juvenile crust generation and crustal reworking.There are at least three periods of greenstonerelated magmatism in the Yilgarn Craton.The earliest recognised greenstone development consists of volcanic and sedimentary successions deposited between c.3000–2900 Ma.A mantle plume at c.2800 Ma produced large mafic–ultramafic igneous complexes and probably initiated rifting on the eastern side of the craton and incipient rifting in the NW.A second major plume,at c.2700 Ma,was focussed along the rupture created by the c.2800 Ma event and may have been associated with the re-accretion of lithospheric blocks created by the earlier event.Komatiites generated by the c.2700 Ma plume contain world-class Ni deposits,and structures developed subsequent to the peak of plume activity host world-class Au deposits.Recent studies of Ni and Au deposits in the Eastern Goldfields Superterrane have shown how features ranging in scale from the lithosphere to regional structural and stratigraphic controls to local volcanological and sedimentological variations can affect the size and distribution of deposits.This understanding is now being applied in exploration targeting.
