The　Xiemisitai-Shaerbuerti　Mountain　region,　located　in　West　Junggar,　Xinjiang,　China,　represents　an　important　part　of　the　Central　Asian　Orogenic　Belt　(CAOB).　From　the　Silurian　Pridoli　epoch　to　early　Devonian,　a　set　of　basin　filling　sequence　transitioning　from　marine　flysch　to　shelf　carbonate　is　deposited　in　this　region.　The　spatial-temporal　distribution　of　the　sedimentary　system　and　analyses　of　lithofacies　and　sources　can　provide　evidence　for　reconstructing　the　paleogeographic　configuration　of　western　Junggar　and　the　evolution　of　the　Paleo-Asian　Ocean.　This　study　conducted　a　detailed　analysis　of　lithofacies,　sandstone　clasts,　as　well　as　major　and　trace　elements　in　the　Mangkelu　Ⅱ　section　of　the　Shaerbuerti　Mountain　area　to　explore　the　sedimentary　basin＇s　evolution,　tectonic　background,　and　provenance　attributes.　The　Mangkelu　Ⅱ　section　consists　of　the　Wutubulake　Formation　at　the　bottom　and　the　Mangeer　Formation　at　the　top.　The　facies　successions　from　bottom　to　top　includes　slope–basin　background　deposits,　basin　turbidites,　hyperpycnal　flow　fans　at　the　shelf　margin,　shelf,　and　shallow　sea　grain　shoal,　representing　an　upward-shallowing　basin-fill　sequence.　The　main　sediments　are　sandstone,　conglomerate,　and　bioclastic　limestone.　The　sandstone　is　mainly　composed　of　feldspar　and　lithics,　with　an　index　of　compositional　variability　(ICV)　of　1.37,　which　is　greater　than　1,　indicating　low　maturity.　The　sandstone　samples　are　enriched　in　large　ion　lithophile　elements　(LILEs)　and　depleted　in　high　field　strength　elements　(HFSEs),　with　a　ratio　of　light　rare　earth　elements　to　heavy　rare　earth　elements　(LREEs/HREEs)　ranging　from　2.89　to　7.41,　averaging　6.15.　The　provenance　and　tectonic　discrimination　diagrams　show　a　mixed　source　of　intermediate-felsic　volcanic　rocks　and　andesites,　derived　mainly　from　continental　and　oceanic　island　arcs.　Volcanic　rocks　from　the　Xiemisitai-Shaerbuerti　Mountain　island　arc　provided　abundant　material　for　the　basin　fill.　The　transformation　of　sedimentary　facies　from　turbidites　to　hyperpycnites　in　the　continental　shelf　may　represent　a　temporary　termination　of　basin　filling　and　the　end　of　subduction　and　collision　during　this　period　in　the　Shaerbuerti　Mountains.　©　2025　The　Editorial　Staff　of　Sedimentary　Geology　and　Tethyan　Geology.　All　rights　reserved.