Sequence stratigraphy and composite sea-level changes in the Zha'ertaishan Group, Guyang, Inner Mongol

Stratigraphic sequences and sequence boundaries are divided for the Zha'ertaishan Group, Guyang, Inner Mongol on the basis of lithological, sedimentary facies and facies sequence approaches.The sequence boundaries consist of the first-, second- and third-o rder sequence boundaries, including transgressive ravinement surfaces and composite exposure-drow ning bounding surfaces. With different scales of sequence boundaries as bounding surfaces, the following sequences have been recognized for the Group:one supersequence, three megasequences and eight sequences.The models for the sequence development and architecture are presented for the different paleogeographic settings of the Zha'ertaishan Group, i. e. siliciclastic shoreline, mixed platform-margin carbonate rocks and siliciclastic rocks, carbonate platform, foreslope and shelf-basin sequences. In addition, the composite sea-level changes and their controls on the sequence development and evolution are also treated in this paper.