LAUSR

Abstract The Yaogangxian tungsten deposit, located in the central Nanling Range, is a well-known vein-type tungsten deposit and has been mined for centuries. This study focuses on the morphology, geochronology, and geochemistry of zircon crystals from wolframite-bearing quartz veins and coexisting alkali-feldspar granite to better understand the source of ore-forming materials and the exact timing of tungsten mineralization. All zircon grains, separated from the muscovite alkali-feldspar granite and the wolframite-bearing quartz veins, show core-to-rim structure. The overgrowth rims of the zircon grains from the muscovite alkali-feldspar granite and the wolframite-bearing quartz veins have crystallization ages of 133.4 ± 1.3 Ma and 133.7 ± 1.3 Ma, whereas the relict cores have ages of 155.3 ± 1.6 Ma and 154.8 ± 1.6 Ma, respectively. The ages of the cores are identical to the crystallization age of the hosting Yaogangxian biotite monzogranite. Thus, these cores were derived from the biotite monzogranite, whereas the overgrowth rims should have crystallized during the intrusion of muscovite alkali-feldspar granite and wolframite-bearing quartz veins. The geochemical consanguinity and similar ages of the muscovite alkali-feldspar granite and the ore veins suggest that they were both formed from the highly-fractionated granitic magma in an extensional setting. This highly-fractionated granitic melt might be extracted from the biotite-monzogranitic mush in a long surviving deep-seated magma chamber.