DIAGENETIC CHARACTERS OF MIDDLE-LOWER JURASSIC SYSTEMS AND THE DENUDED THICKNESS OF OVERLYING SEQUENCES IN LIUZHILANGDAI AREA, GUIZHOU PROVINCE

The diagenetic characters and the diagenesis stages of Middle and Lower Jurassic mudstones, Zhiliujin Group quartzose sandstones and Shaxi For-mation feldspathic sandstones in Liuzhilangdai Area, Guizhou Province are described in this paper. Since the denuded sequence would influence on the underlying strata before the denudation,some diagenetic marks would be surely remained in the residual strata. According to the analysis of the diagenetic marks and the correlation to relative diagenetic marks in certain known burial depth area, the thickness of denuded strata are deducted as 1800 meters in this area.