Thermoluminescence Dating of Loess and Tephra from Fairbanks, Alaska

在阿拉斯加中部140ka的老克罗火山上和最古老的C-14年代（约35ka）地层下的黄土和火山，没有一个准确的连续的年代学。相关的地层单元（金溪组及其等效黄土和下伏的上金山黄土）以黄土为主，具有层间不连续的泥层和部分有机层。由于缺乏30-140ka的精确沉积年龄，使得对当地和区域古环境和古生物记录的解释模糊不清。因此，本研究旨在通过对费尔班克斯附近5个地点广泛分布的黄土和间或的互层热释光（TL）测年，为这些沉积物在这个时间范围内建立第一个确定的年代学。还需要额外的实验室设备，以便在这个实验室有效地执行这个和其他TL测年项目。本研究将验证TL测年的可靠性，并获得阿拉斯加一个关键地质区域全新世和威斯康星黄土和泥的TL测年数据。

An accurate and continuous chronology does not exist for the loess and tephra overlying the 140ka-old Old Crow tephra and underlying the oldest C-14 dated (ca 35ka) beds in central Alaska. The relevant stratigraphic units (Goldstream Formation and equivalent loess, and underlying upper Gold Hill Loess) are dominantly loess with interbedded discontinuous tephra and some organic layers. The lack of accurate deposition ages for these sediments in the time period ca. 30-140ka makes interpretation of the local and regional paleoenvironmental and paleontological records ambiguous. This proposal therefore seeks to develop the first firm chronology for these sediments in this time range by thermoluminescence (TL) dating of the widespread loess and occasional interbedded tephra from 5 sites near Fairbanks. Additional laboratory equipment is also requested to permit the efficient execution of this and other TL dating projects in this laboratory. This research will demonstrate the reliability of TL dating and obtain TL dates of Holocene and Wisconsin loess and tephra in a key geologic area of Alaska.