A new method of sedimentary rocks investigation is proposed. It illustrates by means of curves the variations in both time and space of the main mineral and organic features. By combining them together in a logical way, it is possible to decipher the relations between sedimentation and the different factors governing it: depth, distance to shoreline, direction and strength of marine currents, biological and chemical conditions, tectonics and so on. Finally a paleogeographic classiflcation of lithological facies is obtained. Some examples taken in the Gretaceous of the Swiss High Calcareous Alps are presented. The bathymetrical interpretation of their facies is in close agreement with the results of modern oceanographic investigations which have described in some cases very similar conditions.