The Tongbai granulites are present mainly as xenoliths in granodioritic gneisses. The xenoliths with a zircon age of 470Ma are older than host rocks of granoior
The Baoban gold field,located in the area of Hainan Island ,South China ,bears three gold de-posits :Tuwaishan ,Baoban ,and Erjia ,which belong to the wall-rock