The petrographic characteristics of Jingshan "migmatitic granite" and the occurrence of the magmatic zircons indicate that the granite was formed by normal crystallization of felsic melts. All zircons in the...The petrographic characteristics of Jingshan "migmatitic granite" and the occurrence of the magmatic zircons indicate that the granite was formed by normal crystallization of felsic melts. All zircons in the granite have inherited cores and fine-scale oscillatory zoning rims of magmatic origin. It is realized that the granite was formed at 160.2±1.3 Ma through dating magmatic zircons. The generation of the granitic magma could be related to the lithospheric mantle and/or lower crust delamination after the ultrahigh pressure metamorphism (UHPM) in Triassic. Most inherited zircons yield the ages of 217.1±6.6 Ma, which is consistent with the peak UHPM in the Dabie-Sulu orogenic belt. Some of the inherited zircons (433-722 Ma) constitute a discordia line with the upper intercept age of 850+85/-68 Ma and a lower intercept age of 261+100/-140 Ma. These ages imply that the granite could be derived from the partial melting of the crustal materials of the South China Block that was intensively superimposed by the UHPM. The UHPM could be the reason for the major Pb loss at ±220 Ma.展开更多
1 Introduction The early formation and evolution of the North China craton has been widely concerned by scientists.The Bengbu uplift belt is located in the southeast of the craton,theresearch degree of the belt is rel...1 Introduction The early formation and evolution of the North China craton has been widely concerned by scientists.The Bengbu uplift belt is located in the southeast of the craton,theresearch degree of the belt is relatively low and received increasing attention from many scholars in recent years.Through the author’s practical work and combined with展开更多
基金supported by MST(Grant No.TG1999075502)the National Natural Science Foundation of China(Grant No.40172030)Jilin University(Grant No.2002CX004).
文摘The petrographic characteristics of Jingshan "migmatitic granite" and the occurrence of the magmatic zircons indicate that the granite was formed by normal crystallization of felsic melts. All zircons in the granite have inherited cores and fine-scale oscillatory zoning rims of magmatic origin. It is realized that the granite was formed at 160.2±1.3 Ma through dating magmatic zircons. The generation of the granitic magma could be related to the lithospheric mantle and/or lower crust delamination after the ultrahigh pressure metamorphism (UHPM) in Triassic. Most inherited zircons yield the ages of 217.1±6.6 Ma, which is consistent with the peak UHPM in the Dabie-Sulu orogenic belt. Some of the inherited zircons (433-722 Ma) constitute a discordia line with the upper intercept age of 850+85/-68 Ma and a lower intercept age of 261+100/-140 Ma. These ages imply that the granite could be derived from the partial melting of the crustal materials of the South China Block that was intensively superimposed by the UHPM. The UHPM could be the reason for the major Pb loss at ±220 Ma.
基金the project "A study on gold mineralization and prospecting direction in east Anhui province" (item code: 2014-K-5)
文摘1 Introduction The early formation and evolution of the North China craton has been widely concerned by scientists.The Bengbu uplift belt is located in the southeast of the craton,theresearch degree of the belt is relatively low and received increasing attention from many scholars in recent years.Through the author’s practical work and combined with
