Xihuashan intrusion, Dayu Co., Ganzhou Prefecture, Jiangxi Province, China

Jurassic biotite granite intrusion. The exposed area of the granite (19 km2) hosts the Xihuashan and Dangping Mines. The Piaotang mine, located further north, works veins in the contact zone between the granite and overlying country rocks.

The granite comprises two phases, which intruded in Cambrian low-grade metamorphic rocks of psammitic and pelitic origins. The first phase is a coarse grained porphyrytic biotite granite, rich in monazite-(Ce), xenotime-(Y), zircon and uranothorianite. This granite is the mother rock of the fluids for tungsten mineralization. A second phase, medium-fine grained biotite granite (magmatic to hydrothermal stage, final oversaturation of the granitic melt in a fluid phase and F-CO2 enrichment) is mineralized with spessartite (Y-rich), xenotime-(Y), gadolinite-(Y), fergusonite-(Y) and Y-rich fluorite.

References:
- Le Bel, L., Yidou Li, and Jifou Sheng (1984): Granitic evolution of the Xihuashan-Dangping (Jiangxi, China) Tungsten-Bearing system. Mineralogy and Petrology 33(3), 149-167.
- Orris, G.J., and Grauch, R.I. (2002): Rare Earth Element Mines, Deposits and Occurrences. USGS Open-File Report 02-189, 174 pp.
- Rucheng Wang, Fontan, F., Xiaoming Chen, Huan Hu, Changshi Liu, Shijin Xu, and de Parseval, P. (2003): Accessory minerals in the Xihuashan Y-enriched granitic complex, Southern China: A record of magmatic and hydrothermal stages of evolution. Canadian Mineralogist 41, 727-748.
- Guoneng Chen and Grapes, R. (2007): Granite Genesis: In-Situ Melting and Crustal Evolution. Springer Verlag, 278 pp.