Thermoluminescence Dating of Loess and Tephra from Fairbanks, Alaska

一个准确和连续的年表不存在的 黄土和火山灰覆盖在140 ka的老乌鸦火山灰上， 位于中环最古老的C-14年代（约35 ka）的地层之下 阿拉斯加 相关地层单位（Goldstream组 和相当的黄土，以及下伏的上金山黄土） 以黄土为主，夹不连续火山灰层， 有机层。 缺乏准确的沉积年龄， 在这段时间内的沉积物。30- 140 ka解释了 当地和区域的古环境和古生物 记录模棱两可。 因此，这项建议旨在发展 该时间范围内这些沉积物的第一个确定的年代表， 广泛分布的黄土的热释光（TL）测年， 在费尔班克斯附近的5个地点偶尔发现夹层火山灰。 还要求增加实验室设备， 有效地执行这个和其他TL约会项目， 实验室 这项研究将证明TL的可靠性 测定了全新世和威斯康星州黄土的热释光年龄， 火山灰是阿拉斯加的一个重要地质区域。

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.