The Ning-Wu(Nanjing-Wuhu) Basin is one of the most important volcanic basins in the Middle-Lower Yangtze River Valley,eastern China.It consists of four volcanic units,i.e.,the Longwangshan,Dawangshan,Gushan,and Niangn...The Ning-Wu(Nanjing-Wuhu) Basin is one of the most important volcanic basins in the Middle-Lower Yangtze River Valley,eastern China.It consists of four volcanic units,i.e.,the Longwangshan,Dawangshan,Gushan,and Niangniangshan Formations.Their LA-ICP MS U-Pb zircon ages are 134.8±1.8,132.2±1.6,129.5±0.8,and 126.8±0.6 Ma,respectively.Results of this study indicate that all volcanic rocks in the Ning-Wu Basin were formed in the Early Cretaceous from 135 to 127 Ma,lasting 8-10 m.y.No Jurassic volcanic activities occurred in any of the volcanic basins of the Middle-Lower Yangtze River Valley,including the Ning-Wu Basin.These new chronological results provide significant evidence for further study of this region to improve our understanding of Mesozoic tectonic,magmatic,and metallogenic processes of eastern China.展开更多
A paleomagnetic study was carried out on late Jurassic sediments in the Nanjing area. Stepwise thermal demagnetization was used to isolate the characteristic higher temperature component （HTC）（D=354.0°,I=48.5&...A paleomagnetic study was carried out on late Jurassic sediments in the Nanjing area. Stepwise thermal demagnetization was used to isolate the characteristic higher temperature component （HTC）（D=354.0°,I=48.5°,a95=7.8°）,which passes the reversal test.A 24.7±8.7°counter-clockwise rotation relative to the Sichuan area is detected through comparing this new pole（84.4°N,7.0°E, A95=7.7°）with other coeval poles reported from South China.This rotation was conducted by sinistral action of slip faults.These cases presenting in several areas of eastern China indicate that deformation of eastern China is under the effect of subduction from the Pacific Ocean plate.The difference on the paleolatitude of several areas across the Tan-Lu fault zone is calculated and suggests about at most 250 km offset distance after the later Jurassic.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40830426,40803015)Deep Exploration Technology and Experimentation (Grant No. Sinoprube-03-02-05)+2 种基金Anhui Public Geologic Projects (Grant No. 2007-1)New Century Excellent Talents in University (Grant No. NCET-10-0324)Scientific Research Project of Centre of Excellence in Ore Deposits,University of Tasmania (Grant No. CODES2009 P2.N3)
文摘The Ning-Wu(Nanjing-Wuhu) Basin is one of the most important volcanic basins in the Middle-Lower Yangtze River Valley,eastern China.It consists of four volcanic units,i.e.,the Longwangshan,Dawangshan,Gushan,and Niangniangshan Formations.Their LA-ICP MS U-Pb zircon ages are 134.8±1.8,132.2±1.6,129.5±0.8,and 126.8±0.6 Ma,respectively.Results of this study indicate that all volcanic rocks in the Ning-Wu Basin were formed in the Early Cretaceous from 135 to 127 Ma,lasting 8-10 m.y.No Jurassic volcanic activities occurred in any of the volcanic basins of the Middle-Lower Yangtze River Valley,including the Ning-Wu Basin.These new chronological results provide significant evidence for further study of this region to improve our understanding of Mesozoic tectonic,magmatic,and metallogenic processes of eastern China.
基金funded by postdoctoral and momentous subject research seed money from Northwestern University and (Structure and oil-gas foreground of south China) from China Petrochemical Corporation
文摘A paleomagnetic study was carried out on late Jurassic sediments in the Nanjing area. Stepwise thermal demagnetization was used to isolate the characteristic higher temperature component （HTC）（D=354.0°,I=48.5°,a95=7.8°）,which passes the reversal test.A 24.7±8.7°counter-clockwise rotation relative to the Sichuan area is detected through comparing this new pole（84.4°N,7.0°E, A95=7.7°）with other coeval poles reported from South China.This rotation was conducted by sinistral action of slip faults.These cases presenting in several areas of eastern China indicate that deformation of eastern China is under the effect of subduction from the Pacific Ocean plate.The difference on the paleolatitude of several areas across the Tan-Lu fault zone is calculated and suggests about at most 250 km offset distance after the later Jurassic.
