Provenance and tectonic setting of Late Carboniferous clastic rocks in West Junggar, Xinjiang, China: A case from the Hala-alat Mountains

The Late Carboniferous palaeo-tectonic setting of the West Junggar region is comprised of arcs alternating with basins. Geochemical analysis of the sedimentary rocks associated with these arc-related basins was conducted to better constrain the provenance and tectonic setting.Major and trace element geochemistry data of Late Carboniferous mudstones and sandstones in the Hala-alat Mountains suggest that these sedimentary rocks and their source areas are characterized by the following four features: (1) sediments experienced a simple recycling process; (2) a low degree weathering conditions in the source areas; (3) compositional immature of the sedimentary rocks; (4) dominated by intermediate to felsic provenance, with a few intermediate to mafic sediments. Integrated with the palaeo-flow data and previous authors’ works, a fore-arc basin model is proposed for the tectonic setting of the sedimentary rocks. The Sawur arc is the primary provenance and supplies the major intermediate to felsic detrital fragments. The Bozchekul-Chingiz arc and Kexia oceanic island arc are the other two secondary sources.

► Geochemistry data are applied to discuss the provenance and tectonic settings. ► The primary source of sedimentary rock is intermediate-felsic rock. ► Geochemistry and palaeo-flow data indicate that the Sawur arc is the main source. ► The Bozchekul-Chingiz arc and Kexia Oceanic island arc are the secondary sources. ► The sedimentary rocks deposit in a fore-arc basin.