Depositional environment and tectonic setting of source area of Tireaili formation in the middle west Kunlun orogenic belt

A section of Upper Carboniferous low-grade metamorphic clastic rocks in the Tireaili formation is found in the middle west Kunlun orogenic belt. It is surrounded by the Triassic igneous rocks. Study of depositional environment and source characteristics of sediment in this formation is significant to tectonic setting of this area. Through fine profile measuring, sedimentary facies signs, mineral identification, and geochemical analysis, we found that this clastic developed Bouma sequence which is low compositional maturity. This clastic rocks is set near the slopes of the provenance gravity flow deposits, and the provenance is complex, which mainly includes recycle transition, dissected arc and transitional arc source area. The tectonic environment include active continental margins and continental island arc, it displays the characteristic of back-arc basin in active continental margin.