Upper Carboniferous Meter-Scale Cyclic Characteristics and Sequence Stratigraphy in the Southwestern Margin of Tarim Basin

Based on previous results and detailed study on the profiles in the Southwestern Margin of Tarim Basin,the sequence stratigraphy in the Upper Carboniferous sections was addressed using the outcrop-based sequence stratigraphy.The results shows:(1) abundant carbonate meter-scale cyclic sequences occurs in carboniferous stratum of southwestern Tarin basin,and can be divided into four types:limestone-marl meter-scale cyclic sequence,deep-water asymmetric carbonate meter-scale cyclic sequence,subtidal carbonate meter-scale cyclic sequence and tidal flat carbonate meter-scale cyclic sequence.(2) the main sequence boundary found in carboniferous stratum of this area is drowned unconformity type,which was formed when relative sea level rise rapidly;while exposure type of sequence boundary can also be found,which was formed when relative sea level fall very fast.(3) different meter-scale cyclic sequences were developed within three different system domains and presents three-level cyclic sequences in the vertical dirction.