Provenance, weathering conditions, and tectonic evolution history of the Cambrian meta-sediments in the Zhuguangshan area, Cathaysia Block

The sandstones and mudstones display K2O enrichment, but they are moderately to extremely depleted in Na2O, CaO and Sr. The major and trace elements reveal that the sandstones and mudstones were derived from recycled felsic rocks and deposited in the passive continental margin. The compositions of the protoliths are inferred equivalent to andesite to granodiorite. The petrographic and geochemical features indicate that the sandstones and mudstones have undergone medium to intensive chemical weathering. Conversion of aluminous clay minerals to illite is inferred to be the predominant post-depositional potash metasomatism.