Genesis and comparative analysis of modern asymmetric ripple marks:an example from the eighth rock formation of the Lower Cretaceous strata in the Honggucheng region of the Minhe Basin

The comparative analysis has been made on the modern asymmetric ripple marks along the Huanghe River exemplified by the eighth rock formation of the Lower Cretaceous strata in the Minhe Basin. The formation here are interpreted as the deltaic plain deposits rather than the shallow-water deposits. Therefore the asymmetric ripple marks are not considered as the products deposited in a specific sedimentary environment,but widespread in various sedimentary environments. More attention should be drawn on the synthetic analysis, comparative analysis, element analysis and systems tract analysis so that the palaeoenvironmental interpretation of the lithostratigraphic units in sedimentary basins may be viable.