摘要：In the weathering crust of carbonate platform margin,the difficulty in calculating denudation volume leads to the difficulty in restoring sedimentary palaeogeomorphology.Based on traditional paleo-geomorphological restoration methods-the residual thickness method and impression method,a new method-Superficial Denudation estimate method-has been proposed for the restoration of sedimentary palaeogeomorphology.The new method utilizes the feature that the reciprocal of impression thickness has the same change trend as the denudation amount.The reciprocal is used as a substitute for denudation and multiplied by the residual thickness to obtain the relative original formation thickness.Then we use sedimentary inheritance principle to eliminate primitive stratum thickness false caused by phase change.Thus,the value of sedimentary palaeogeomorphology is obtained.An example of Dengying Formation in Sichuan Basin is given,the new method is used to restore the sedimentary paleotopography.The favorable reservoir development areas in the study area are pointed out,and the reason of low production efficiency in MX47 well area is explained.The results show that the new method can better characterize sedimentary palaeogeomorphology,comparing with traditional method.And relative thickness method emphasizes the comprehensive analysis of the pal-aeogeomorphological change process from pre-deposition to post-deposition and then to post-denudation,which can eliminate some misunderstandings caused by regional difference denudation in the traditional method,and the relationship between palaeogeomorphology and reservoir can be studied more accurately.Relative thickness method is mainly applicable to the partially denuded carbonate platform margin,when applied in other areas,attention should be paid to the differences in geological significance of the stratum thickness which is used in the method.
关键词：Carbonate platform margin;sedimentary paleogeomor-phology;weathering crust;superficial denudation estimate method;Gaoshiti-Moxi area
