The geographical distribution and physical properties of Qionglei tektites from South China are described in the present paper. 12 samples of Qionglei tektites have been determined for major and minor elements such as A1; Ba, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, La, Mg,Na, O, Rb, Sb, Sc, Si, Sin, Ta, Tb, Th, U, Yb, etc. by NAA techniques. The family to which the tektites belong correlations between main oxides and SiO2, relative REE abundances, REE distribution patterns, Th/U ratios, and their bearing on the evolutionary history and genesis of Qionglei tektites are also discussed.
A brief account is given to the principle of delayed fission neutron method and the related equipments for the determination of uranium in minerals by this method. The whole experimental procedure was autoprogramatically controlled. The neutron flux was monitored and delayed fission neutrons were measured in a multiscale mode by multichannel analyser. The method has the advantage of relative simplicity, quick performance, high accuracy, non-destructlon and low cost. Its standard deviation is ±0.2% and sensitivity 388 n/μg U. The comparison shows that the results obtained by this method are in good agreement with those by other methods. Finally, the problem of interference in measurement is discussed, too.
