Improving the Precision and Extending the Age Range of Luminescence Dating of Pleistocene Sediment

小行星9809354 对于40-50 ka（放射性碳测年的通常极限）以上的更新世陆地沉积物，缺乏准确和精确的数字测年技术。 未加热沉积物的发光测年方法有可能（基于动力学研究）直接确定碎屑-长石埋藏时间远超过1 ma，这一时间段至少包括更新世的一半，因此有许多冰川-间冰期循环。 该奖项支持使用新的，更精确的红外线激发发光（IRSL）测年程序对黄土样品进行高精度测量。 在IRSL测年的规定时间范围内（400 Ka），该方法有望使黄土释光测年精度提高一倍以上。 伴随热释光（TL）的测量将在几个样品，以验证以前的TL结果，并提高其精度，使用最近的TL实验协议。 此外，还将对从阿拉斯加和育空地区（加拿大）采集的新黄土样品进行TL和IRSL测量。 这些网站有新记录的独立的数字年龄高达2马，根据古地磁极性反转边界和裂变径迹年龄的火山灰床。 更新世陆缘晶石发光测年法的改进应有助于全球从更新世陆地记录中提取时间序列数据的努力。

9809354 Berger There is a dearth of accurate and precise numeric dating techniques for Pleistocene terrestrial sediment older than 40-50 ka, the usual limit of radiocarbon dating. Luminescence dating methods for unheated sediment have the potential (based on kinetics studies) to directly date detrital- feldspar burial time to well beyond 1 ma, a time period embracing at least half the Pleistocene and therefore many glacial-interglacial cycles. This award supports high- precision measurements on loess samples using the new, more precise, infra-red- stimulated-luminescence (IRSL) dating procedure. Use of this method is expected to improve luminescence- dating precision for loess by more than a factor of two, in the established time range for IRSL dating (400Ka). Companion termoluminescence (TL) measurements will be made on several samples to validate previous TL results and to improve their precision using more recent TL experimental protocols. Furthermore, both TL and IRSL measurements will be made on new loess samples to be collected from sites in Alaska and the Yukon Territory (Canada). These sites have newly documented independent numerical ages up to 2 Ma, based on paleomagnetic polarity-reversal boundaries and fission track ages of volcanic ash beds. Improved luminescence dating of Pleistocene terrestrial feldspars should benefit global efforts to extract time-series data from much of the Pleistocene land record.