In order to continue our investigation into the possible utility of induced thermoluminescence as a chronometer for volcanic activity we have measured the induced thermoluminescence properties of twenty-eight samples collected from the almost 3 km long Blue Dragon flow at Craters of the Moon National Monument and Preserve, Idaho. The properties of the samples are consistent with previous conclusions that the major mineral causing the luminescence is feldspar and that variation in the glow curves (light emitted as a function of heating temperature) is caused by variations in the thermal history of the samples. However, in nine of the 28 samples a there is a significant contribution to the TL signal from apatite. The induced thermoluminescence level along the flow is essentially constant, showing at most a factor of four decrease from beginning to the end (from ∼16 to ∼4, on a scale of the Dhajala meteorite = 1000), and this is not statistically significant. Thus sampling distance from the vent should not be a problem for the proposed TL dating method. However, there are details that might pose a problem for dating. (1) There is considerable (factor of 10 or so) scatter in the TL data due to the high heterogeneity of the samples. (2) There are abundant highly luminescent spherules which could explain some of the scatter; however, they are restricted to samples taken very close to the vent and could be screened from TL samples using cathodoluminescence, a microscopic means of identifying components producing the TL. (3) There is a factor of three increase in crystallization along the core (from ∼20 vol% to ∼60 vol%) but no factor of three increase in induced TL value. This is additionally problematic because crystallization is accompanied by a small decrease in anorthite content of the feldspar which should further increase induced TL values. While empirical data suggest that there is a weak correlation between induced TL and age for volcanics from Idaho and Hawaii, our detailed study of the Blue Dragon flow removes one complication for the dating method but reveals many details that need to be kept in mind as this possible dating method is explored. Most importantly, we need a method for reducing the scatter in induced TL displayed by samples from a single volcanic eruption.

中文翻译：

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诱导热释光作为测定近期火山活动的方法：美国爱达荷州蓝龙流以及影响诱导热释光的因素

为了继续研究诱导热释光作为火山活动计时器的可能性，我们测量了从月球陨石坑国家纪念碑和保护区近 3 公里长的蓝龙流中收集的 28 个样本的诱导热释光特性，爱达荷州。样品的性质与之前的结论一致，即引起发光的主要矿物是长石，并且辉光曲线的变化（作为加热温度的函数发出的光）是由样品的热历史的变化引起的。然而，在 28 个样品中的 9 个样品中，磷灰石对 TL 信号有显着贡献。沿着流动的诱导热释光水平基本上是恒定的，从开始到结束最多减少四倍（从 ~16 到 ~4，在 Dhajala 陨石 = 1000 的范围内），并且这在统计上并不显着。因此，对于所提出的 TL 测年方法来说，距排气口的采样距离不应成为问题。然而，有些细节可能会给约会带来问题。 (1) 由于样本的高度异质性，TL 数据存在相当大的分散性（10 左右）。 (2) 存在丰富的高发光球体，可以解释部分散射；然而，它们仅限于在非常靠近排气口采集的样品，并且可以使用阴极发光（一种识别产生 TL 的成分的微观方法）从 TL 样品中筛选出来。 (3) 沿着核心的结晶度增加了三倍（从〜20 vol%到〜60 vol%），但诱导的TL值没有增加三倍。这也是一个问题，因为结晶伴随着长石中钙长石含量的小幅下降，这会进一步增加诱导的TL值。虽然经验数据表明，诱导 TL 与爱达荷州和夏威夷火山的年龄之间存在微弱的相关性，但我们对蓝龙流的详细研究消除了测年方法的一个复杂性，但揭示了许多需要牢记的细节，因为探讨了可能的约会方法。最重要的是，我们需要一种方法来减少单次火山喷发样本所显示的诱导 TL 的分散性。