Delineation of unconformities and stratigraphic limits in carbonate organogenic sections on the basis of analysis of layer thickness variations

The authors propose to improve the ways of unconformities and stratigraphic limits delineation in carbonate organogenic sections on the basis of analysis of layer thickness variations. Materials of sedimentological analysis of natural outcrop cross-sections characterised in detail by lithological, geochemical, and paleontological data are used in this work. The cross-sections used are unique as they characterise the carbonate sequence structure within three different depositional zones of the basin, they are comprehensive, and based on layer-by-layer analysis at an interval of one metre. Process of the section formation is simulated using a diagram of layer thickness changes, which shows the layer-by-layer accumulation of deposits and takes into account their post-depositional transformation. Diagrams of thickness changes are composed of segments having different lengths and slope angles. The segments correspond to the layers; position of the layers is specified by the depth of their beginning and end (layer Top and Bottom). Change in thickness of overlaying bed is shown in the diagram by the change in