Discovery of high-REE calcites in the Dachang superlarge tin-polymetallic ore deposit, Nandan, northwestern Guangxi

The Dachang tin-polymetallic ore deposit, Guangxi, is one of the largest tin deposits both in China and abroad, with its reserves of Sn, Zn, Sb, As, Ag, In and Ga reaching large or superlarge size. This paper reports the new results of studies on rare earth elements (REE) in nonmetallic minerals of the orebodies 91#, 92# and 100# orebody in the Dachang mining area. The authors find that there exist special calcites with high REE contents in the 91# and 92# orebodies. The REE content may reach a maximum of 940.42×10-6 with an average of 799.2 ×10-6. Generally, high REE contents of calcites have a genetic relationship with mantle-derived fluids. So, the existence of the special calcite with a high content of REE in the Dachang mining area suggests that mantle-derived fluids may have contributed to the formation of this deposit.