直接蒸发单颗粒锆石测定~(207)Pb/~(206)Pb年龄的方法

在双带源热离子发射质谱计上,用Kober,B.(1987)建立的方法直接蒸发锆石测定~(207)Pb/~(206)Pb表面年龄。4件已知年龄的锆石样品测定结果表明,用该方法测定的年龄值与常规锆石U-Pb一致曲线的上交点年龄一致。使用腈基丙烯酸酯粘合剂,使得装样简单、可靠,并可增加铅离子流强度。文中首次报道了湖北广水蔡家河小河岩体、黄土寨岩体中锆石的形成年龄。

DIRECT DETERMINATION OF ~(207) Pb/~(206)Pb APPARENT AGE BY SINGLE ZIRCON EVAPORATION

The 207 Pb/206Pb apparent ages for 4 samples were measured by double filament thermal evaporation mass spectrometer, this technique was established by Kober, B. in 1978. The data of these samples are comparable to that obtained by the U -Pb conventional method. By using the cyanoacrylate adhesive, loading sample becomes easy and reliable, the intensity of ion current increases by 1-2 orders of magnitude. The apparent-age of zircon from Xiaohe granite diorite gneiss and Huangtuzhai adamellite gneiss in Caijiahe, Guangshui, Hubei, are reported for the first time in this paper.