Hi, you can use the diagrams of Bathia (1983) for major elements, Mc Lennan et al ( 1993) and Roser & Korsch (1986) are used for discriminate tectonic environments and provenance of sediment by major elements. You can use too traza elements with diagrams like Herron (1988), it is used for discrimine types of rocks, mainly sandstones and shales, based in major elements. I did a geochemical study of provenance of cretaceous sandstones using this diagrams.