白云鄂博超大型REE-Nb-Fe矿区碳酸岩墙的侵位年龄——兼答Le Bas博士的质疑

Intrusive age of No.1 carbonatite dyke from Bayan Obo REE-Nb-Fe deposit,Inner Mongolia:with answers to comment of Dr.Le Bas.

对白云鄂博稀土-铁-铌矿矿区一号碳酸岩墙内锆石U-Ph年龄进行了测定,三颗锆石测定数据点拟合直线与谐合线的上交点年龄为1416±77 Ma,它可能表明了白云鄂博矿区火成碳酸岩墙的侵入时代,而另外1颗锆石的表面年龄(1925±8 Ma)则可能是来自围岩的捕获锆石年龄。

Zircon U-Pb age of No, 1 carbonatite dyke from the Bayan Obo giant REE-Nb-Fe deposit is presented in this study. Three zircon fractions from the dyke well define a discordia giving an upper-intercept model age of 1416±77 Ma. This model age is interpreted as intrusive time of the carbonatite dyke. Apparent age of one zircon （ 1925 ± 8 Ma） is presented as trapped old zircon coming from wallrocks,