Abstract Alpha irradiation is less efficient in inducing the thermoluminescence (TL) signal compared to beta and gamma irradiation. Although TL dating has been applied to calcite from various geological contexts, studies of the alpha effectiveness (a-values) of calcite are relatively scarce, and the reported a-values are focused on the 280 °C TL peak of speleothem calcite. In this study, three single-aliquot regenerative-dose (SAR) protocols were applied to measure the a-values of the 280 °C TL peak, the 350 °C TL peak, and the isothermal thermoluminescence at 240 °C (ITL240) of calcite from travertine, limestone and marble samples. The performances of the three SAR protocols were compared and the ITL240 signal was generally equivalent to the 280 °C TL peak TL. The a-values of the 280 °C TL peak of the samples range from 0.19 to 0.24, with a mean value of 0.20 ± 0.01, which are within the range of a-values previously reported for speleothems. The a-values of the ITL240 signal are slightly higher, and the mean value is 0.23 ± 0.01. However, the 350 °C TL peak has a lower mean a-value of 0.15 ± 0.01. The dose response curves for the 280 °C TL peak, 350 °C TL peak and ITL240 signal of the samples have characteristic saturation doses (D0) of 3000–5000 Gy, showing great potential for dating samples millions of years old.

中文翻译：

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方解石的热释光测年 – Alpha 有效性和测量方案

摘要 与 β 和 γ 辐射相比，α 辐射在诱导热释光 (TL) 信号方面效率较低。尽管 TL 测年已应用于来自各种地质背景的方解石，但对方解石 alpha 有效性（a 值）的研究相对较少，并且报告的 a 值集中在 280 °C 的 seleothem 方解石 TL 峰上。在本研究中，应用三个单等分再生剂量 (SAR) 协议来测量 280 °C TL 峰、350 °C TL 峰和 240 °C 下的等温热释光 (ITL240) 的 a 值钙华、石灰石和大理石样品中的方解石。比较了三种 SAR 协议的性能，ITL240 信号一般相当于 280 °C TL 峰值 TL。样品 280 °C TL 峰的 a 值范围为 0.19 至 0.24，平均值为 0.20 ± 0.01，在先前报告的洞穴动物 a 值范围内。ITL240信号的a值略高，平均值为0.23±0.01。然而，350 °C TL 峰的平均 a 值较低，为 0.15 ± 0.01。样品的280°C TL峰、350°C TL峰和ITL240信号的剂量响应曲线具有3000-5000 Gy的特征饱和剂量（D0），显示出对数百万年前样品测年的巨大潜力。