THE STORM-RELATED ICHNOFACIES IN THE DEVONIAN STRATA IN SOUTHERN GUIZHOU

The trace fossils abound in the storm deposits of the Devonian strata in Southern Guizhou.The detailed research was conducted in order to improve our knowledge of the storm-related ichnofacies. The strength and duration time of storm processes tend to affect the physical and chemical conditions of sedimentary environments and give rise to the changes in trace fossil assemblages.The present paper describs the storm-related trace fossil assemblages in Glos-sifingites,Skolithos,Cruziana and Zoophycos ichnofacies of Seilacher(1967)in the Devonian strata in Southern Guizhou.Three types of storm-related ichnofacies have been distin-guished.(1)The monotype storm-related iehnofacies resulted in the environments where the storm processes are relatively weak.The trace fossils decrease in genus and species and amount in the ichnofacies,and appear mainly in Seilacher's Skolithos and Cruziana ichnofa-cies.(2)The mixed storm-related ichnofacies means that a new ichnofacies formed during storm deposition is superimposed upon the preexisting lower-energy ichnofaeies.(3)The mixed multiple storm-related ichnofacies implies that more than two storm-related ichnofa-6ies occur simultaneously during storm deposition in response to the increasing strength of storm processes.