Abstract:
This paper focuses on the relationship between sequence stratigraphy and compilation of lithofacies and palaeogeographic maps. The Devonian strata in southern China may be divided into four depositional sequences in terms of sequence boundary unconformity characterized by fluvial rejuvenation and condensed sections consisting of biostrome and tentaculitid-bearing siliceous rocks. Their times are represented by the Lochkovian to middle Emsian, late Emsian to early and middle Givetian, late Givetian to Frasnian and Famennian, respectively.
The depositional sequences cited above are time-equivalent because the sequence boundary unconformity and the boundary between the depositional systems tract are time-equivalent. Therefore, the lithofacies and palaeogeographic maps compiled on the basis of the point of view and method of sequence stratigraphy approximately coincide with the distribution of seas and continents, indicating the framework of sedimentary facies and the associated information about sedimentation and tectonic activity in the basin and basin evolution. The compilation of the Devonian lithofacies and palaeogeographic map of South China has been made by means of the depostional sequences as the basic chronostratigraphic units, the depostitional systems tract as the compilation unites, the sequence boundary unconformity as the isochronous or instantaneous surfaces, and distinctive sedimentary facies in the depositonal systems tract as the compilation elements of the corresponding isochronous surfaces.