中国中-新元古代地层年表的修正——锆石U-Pb年龄对年代地层的制约

报道了全国地层委员会的中-新元古代地层年表新标定的方案:即长城系限定在1.8～1.6 Ga;蓟县系限定在1.6～1.4 Ga;待建系1.4～1.0 Ga;青白口系限定在1.0～0.78 Ga;南华系限定在780～635 Ma及震旦系限定在635～542 Ma.新年表突出3个方面的标定:1)对长城系和蓟县系的年代学限定;...

NEW GEOLOGIC TIME SCALE OF MESO-AND NEOPROTEROZOIC OF CHINA AND GEOCHRONOLOGIC CONSTRAINT BY SHRIMP ZIRCON U-Pb DATING

On the basis of the new remarked the Precambrian stratigraphical column of China,which is discussed by the National Commission on Stratigraphy of China on Aug.,2010.The Changcheng System is limited in 1.8～1.6 Ga. The Jixian System is limited in 1.6～1.4 Ga.Unnamed system(1.4～1.0 Ga) only developed the Xiamaling Formation in the Jixian section.The Qingbaikou System is limited in 1.0～(0.78 Ga.) The Nanhua System is in 780～635 Ma and The Sinian System is in between 635～542 Ma.There three important markers in the new geologic time scale.1) The Changcheng System and the Jixian System are reformed in it; 2) According to the SHRIMP zircon U-Pb dating,the unnamed system is left in the time scale;and 3) the lower boundary age of the Nanhua System is limited at 780 Ma.Because the big problems is the strata division and correlation in restudy of new regional geology in each provinces by Chinese Geological Survey and according to the new geologic time scale of Meso and Neoproterozoic of China,it is big changes in Precambrian strata correlation and tectonic explanation.According to new zircon U-Pb dating found in North China Plate,Yangtze Plate and Talimu Plate,it primary shows the volcanic province and distribution.Dealing with the basic global geodynimics,it is useful to set up a basic late Precambrian section of unify,practical and high precision chronological dating.