Controls on the REE tetrad effect in granites: Evidence from the Qianlishan and Baerzhe Granites, China.

Abstract

REE contents in whole-rock samples and constituent minerals of the Qianlishan and Baerzhe granites from China were determined using three analytical methods (ICP-AES, ICP-MS, and ID-TIMS). The REE abundance patterns of the granites show the M-type tetrad effect and strong Eu depletion in both whole-rock samples and in individual minerals samples. Fluid-melt interaction in the late stage of fractional crystallization is suggested to be the most important factor controlling the formation of REE tetrad effects in the granites.