Trace Fossils and Transgressive Deposits，Transgressive Systems Tracts in Tataertage Formation ( Lower Sil urian )，Tarim Basin

Key words: 
• trace fossil /
• transgressive systems tracts /
• Tataertage formation /
• facies assemblage /

Abstract: Transgression has been routinely regarded as to be rapidly accomplished，relatively simple in successionand commonly characteristic of deposit. Study on trace fossils and sedimentary features of Tataertage Forma-tion indicated that transgressive systems tracts possess their own unique complexities and can be grouped intothree main subdivisions:(1)the first group of fades is produced by the process of transgressive erosion includ-ing transgressive lags with Glossifungites ichnofacies;(2) the second one corresponds to those sediments de-posited while relative sea level is rising slowly or related to the stillstand cycle during an overall transgression，including foreshore and shoreface sandstones as well as mudstones with Skolithos ichnofacies and proximalCrzcziana ichnofacies(3)the last one reflects the rapid rising of relative sea level including offshore mudstoneswith distal Cruziana ichnofacies.