Discussion on Geotectonic Controlled SedimentationBased on Geotectonic Evolution of Precambrian in Estern China

This paper deals wth the development of the Archean and Early Proterozoic rock units and their be-tween tectonic features. and then discusses the relationship tectonic environment and sedimentation.The au-thors emphasized that the ancient sedimentation may be controlled by tectonic settings There are three tectcnic cycles in Precambrian occurred in eastern China, termed Qianxi. Fuping andWutai.The ancient continental crust of that period may be fotzrted just in the regions of northern China.It issuggested that, in the studying of Precambrian earth crust should be considered the tectonic settings whichassociated with sedimentary environment.For the high temperature and pressure existing in the mantle. it isbelieved the komatiite was formed in Archean, and the greenstone belt which widely spread may representedthe stablity of cratonic regions.Based on the results of investigations of Archean metamorphic sequence forseveral years, it suggests that the development of nuclei of ancient continents may be with progression andcertain tendency, such as depletion of vertical movement and increase of horizontal movement with ume.lnaddition, the characters of deformation may be from plastic change into rigid ones, thus. un thesynclinoria in NE trend stacked some fractures and led to formed pruto-taphrogens. to、、hich the EarlyProterozoic strata had been deposited, the location of w hich was at the continental margins andintracontinental settings.This tectonic pattern of framework had controlled the formation of the Pruterozoicsediments dunng that period.However, the carbonate rocky can be represent the differentanon of the ancientearth crust, such as Wutai Group which consists of basic to acidic volcanics and elastics interbedded withsome carbonate rocks, as well as with rhythmic flysch feature.The regional metamorphism is mainly derivedfrom Wutai Movement stage 1. During the Stage LI and Luhang Movement, because of the strength oftectonic movement had been depleted, there isn' t obvious regional metamorphism. The enlarging andthickening of continental crust ctiused by' tectono-thermal events, are likely to form some nuclei of ancientcontinents worldwidelv In summary，ti is emphusized that m the studying of Precambn.m wstem. the uniformitarianism is notsuitable to adapt, because of the characteristics of the earth' s crust is山fferent from the latter plates which was formed in Late Puleozoic