Trace and rare earth element geochemistry of Jurassic mudstones in the northern Qaidam Basin, northwest China

Trace and rare earth element (REE) of Jurassic mudstones from the northern Qaidam Basin of northwest China were measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis. The analytical results show that the trace element and REE concentrations are higher than in the average of the upper crust. Three aspects evolved: (i) the paleoclimate index, Σ(Fe + Mn + Cr + Ni + V + Co)/Σ(Ca + Mg + Sr + Ba + K + Na), varies between 0.27 and...