Analysis Of Multi-Scale Cyclicity Formation

This paper, guided by sedimentology, sequence stratigraphy and cycle stratigraphy, taking the well logging data as the main object of study, discussed the application of wavelet analysis, cluster analysis and discriminant analysis in the recognition of cycle, analied the reason why cyclothem produced, and researched the different cycles according to the criterion.On the basis of analytical study log information, taking Matlab as a platform, the paper realize the lothological determination using cluster analysis and discriminant analysis. Through statistical analysis of well in Jiyang down warping region, the average thickness of lithological cycles was obtained. The possibility of belong to spins or allogenetic cycle was discussed.According to the shape of typical log, on the basis of constructing of ideal log model, with the analysis of lothological analysis, the paper divided the sedimentary facies using one-dimentional continual wavelet transformation. Then, sedimentary subfacies thickness of Shahejie group in Jiyang down warping region was statistically analysed, and the average thickness of deposition subfacies cycle was obtained.The paper realized the sequence division and recognition of Milankovitch cycle with one-dimentional continual wavelet transformation mold extreme value, and carried on the confirmation through the constructing ideal signal model for this method's validity. The different well log in Jiyang down warping region were analysed, and the average thickness of the sequence, the accurate sequence, and precession, obliquity and eccentricity of Milankovitch cycle were obtained by the comparison and the statistical analysis. It was discovered that there were differents in Milankovitch cycle that preserved in the stratum of Es and Mesozoic, the reason of which was analysed.Through comprehensive analysis and comparison and according to the multi-scale cycle thickness, the paper infed that it had corresponding relations between lithology, sedimentary facies, sequence and Milankovitch cycle as follows:as the smallest unit in strata, the lithology cycle can be corresponding with precession cycle and sedimentary micro-facies in Milankovitch cycle; subsequence can be corresponding with sedimentary microfacies or sedimentary subfacies and eclipticobliquity cycle; parasequence sets can be corresponding with sedimentary subfacies and eccentricity short cycle; if sequence can be corresponding with sedimentary facies and eccentricity long cycle depends on further research.