华北地台沉积盖层的构成及演化

Constitution of Rocks and Evolution of Sedimentary Cover in North China Platform

本文统计了华北地台盖层不同时代沉积地层的体积和质量，计算了其构成。并与世界主要地台区进行了对比，探讨了其体积、质量、构成的演化及其控制因素。通过显生宙沉积岩循环率的计算，进一步论证了盖层的发育主要是沉积岩本身的循环。

Abstract This paper has discussed volumes and mass of each period sedimentary strata in North China platform. The constitution of rocks has been calculated and compared with other main platform in the world. The sedimentary cover of North China plateform is composed of one/third carbonate and two/thirds terrigenous rocks. The constitution of rocks is similar to Laurasia and North China platform. But there are poor evaporite and extensive distrubution of carbonate. Compared with the earth's sedimentary shell,North China Platform is characterized by that terrigenous rock is rich in clastic rock(41 percent of grass rock volum)and percentage of argillaceous rock is low(26. 7percent of grass rock volum). However. Character of constitute of rocks of each sedimentary take is greatly different from each other,which is determined by special history of geological development in North China Platform.Periodically tectonic and thermal event changed the resource of sedimentary rock and rate of sedimentation. It makes mass,volume constitution of rocks change with tectonic cycle,and is main base of variation of constitute, volume, mass. Only in Longer period of geological time, will the influence of recycling of sediment be obvious. Because the influence of tectonic-thermal event is averaged in this case. The influence of recycling of sediment also exist in the stable period of tectonic activity. Only considering tectonic event and recycling of sediment can we realize the variation of the constitute of sedimentary rocks and mass.Simulating calculation shows that the 90% of sedimentary rock in North China Platform have been recycled during the period of sedimentary cover development which indicates that it is main recycling of sedimentary rocks during sedimentary cover development.