In this study tektites from across the Australasian strewn field (specifically, mainland Australia, Tasmania, Java, Malaysia) have been dated by the fission-track method. Twelve tektites from 9 localities define two age groups: one has a weighted mean age of 822 ± 20 ka based on 12 age determinations, and the other is 655 ± 20 ka based on 10 age determinations. The older group represents formation age of the tektites, and, given its error, is close to the precise ⁴⁰Ar/³⁹Ar age of the Australasian tektites at 788 ± 3 ka. Tektites of the younger group have a widespread distribution, occurring in Australia and southeast Asia. Their major- and trace-element composition is similar to the older tektites and their young age is thought to be due to heating subsequent to their original fall position, probably by wildfires that totally reset the fission-track clock. Soil surface temperatures, in the range of 500–800 °C, have been reported during experimental studies and would anneal all fission tracks in tektites within a few hours. The fission-track age record with its ~10% associated error on individual age determinations cannot precisely link thermal resetting to a particular elevated phase of wildfires. This task must await studies on high-resolution sedimentary sequences deposited around 650 ka. The view that these younger tektites were formed by a second impact event is discounted.

在这项研究中，来自澳大利亚大陆（特别是澳大利亚大陆、塔斯马尼亚、爪哇、马来西亚）的 tektites 已通过裂变径迹方法确定年代。来自 9 个地点的 12 块陨石定义了两个年龄组：一个基于 12 次年龄测定的加权平均年龄为 822±20 ka，另一个是基于 10 次年龄测定的 655±20 ka。较老的一组代表了陨石的形成年龄，并且鉴于其误差，接近精确的⁴⁰ Ar/ ³⁹澳大利亚 tektites 的 Ar 年龄为 788 ± 3 ka。年轻群体的Tektites分布广泛，发生在澳大利亚和东南亚。它们的主要和微量元素组成与较老的 tektites 相似，并且它们的年轻年龄被认为是由于在它们最初的坠落位置之后加热，可能是由完全重置裂变轨道时钟的野火造成的。实验研究中已经报道了土壤表面温度在 500-800 °C 的范围内，并且会在几小时内退火 tektite 中的所有裂变轨迹。裂变径迹年龄记录在个体年龄确定方面具有约 10% 的相关误差，无法准确地将热复位与野火的特定升高阶段联系起来。这项任务必须等待对沉积于 650 ka 左右的高分辨率沉积序列的研究。