Evolution and REE geochemistry of Huangsha-Tieshanlong ore-bearing granite

Abstract

Our studies show that the granite bodies (γ ^{2 − 1}₅ and γ ³₅ ) which constitute the Huangsha-Tieshanlong composite granitic intrusion in Jiangxi are characterized by their similarities in mineral assemblage, petrochemistry, trace element and REE distribution pattern. The values of ΣREE, ΣLREE, ΣHREE, ΣCe/ΣY, δEu and La/Yb apparently decrease from γ ^{2 − 1a}₅ to γ ^{2 − 1b}₅ , γ ³₅ and γ ³₅ . It is shown that the early Yenshanian W(Ta, Nb)-bearing granite (γ ^{2 − 1}₅ ) and late Yenshanian Ta, Nb-bearing granite (γ ³₅ ) may have been derived from the differentiation and evolution of granitic magmas due to repeated remelting of the crust and their earlier and later intrusion. Although the earlier (γ ^{2 − 1b}₅ and later (γ ³₅ ) albitized Ta, Nb-bearing granites show some obvious differences in REE content, their δEu values and La/Yb ratios are similar to each other. Therefore, it may be concluded that the early and late Ta, Nb-bearing granites were derived from a congenetic magma.