Sandstone provenance of north-western sectors of the intracontinental Cenozoic Qaidam basin, western China: Tectonic vs. climatic control

Few selected mudstones from Eocene to Lower Miocene formations have been geochemically analysed by ICP-MS. All samples display uniform high enrichment in light REEs in chondrite-normalized diagrams. With one exception, the REE concentrations are decreasing in a stepwise manner, although insignificantly, from formation to formation with time due to a diluting effect by carbonate.