A preconcentration INAA method is used for the analysis of very low REE concentrations of the Hongguleleng ophiolite and the normal INAA method for the trace elements of the ophiolites. The analyses show that the lherzolite (sample X-49) may be representative of primary mantle

while the harzburgite (sample X-44) is probably the residual mantle material from partial melting of the upper mantle

and the dunite (samples X-55 and X-57) may be accumulated from mafic magma.