THE APPLICATION OF GRAIN SIZE ANALYSIS TO THE CLASSIFICATION OF FAN-DELTAS

In small fault lacustrine basins,the sedimentary fan-deltas are widely spread with a long evolution history and various features.The Paleogene lacustrine basin in the Liaohe Fault could be taken as one of the examples.In this paper,the author quantitatively classified 12 sedimentary fan-deltas of the Liaohe fault basin on the basis of the characteristics of fault development,facies patterns,sedimentary hydrodynamics and lithofacies analysis with the application of the classification and statistics on the probability curves of grain size analysis and six sedimentary types have been divided.Consequently,the classification is not only coincided with the regional structures of the basin and the objective time-space law of the sedimentation,but also reveals the regularities between the nonhomogeneous characteristic parameters of the reservoir beds in the six sedimentary types and those between the features of mining points.Therefore,the established systematic classification model can be regarded as the correlation maker and the prediction model in the reservoir beds of six sedimentary types for their oil/gas exploration and development in early stages.