EXAMINATION OF BULK SOIL AND DETRITAL CHARCOAL, AND AMS RADIOCARBON AGE DETERMINATION OF MATERIALS FROM THE MINTO, DENALI, AND CASTLE MOUNTAIN FAULTS AND THE NORTHERN FOOTHILLS THRUST, ALASKA

Six bulk soil samples from paleoseismic trenches across the Minto Fault, Denali Fault, and Castle Mountain Fault in Alaska were floated to recover and identify organic fragments suitable for radiocarbon age determination. In addition one macrofloral sample and eight detrital charcoal samples from a trench across the Northern Foothills Thrust (Alaska) also were submitted for identification. Botanic components and charcoal fragments were identified and potentially radiocarbon datable material was separated. Seven AMS radiocarbon dates were obtained on charcoal and charred botanic remains from these samples.针对阿拉斯加境内明托断层（Minto Fault）、迪纳利断层（Denali Fault）与卡斯尔山断层（Castle Mountain Fault）沿线的古地震探槽，采集了6份混合土样，经浮选处理回收并鉴定出适用于放射性碳年代测定的有机碎屑。此外，还从阿拉斯加北麓逆冲断层沿线的一处探槽中获取1份大型植物残体样品与8份碎屑炭样品，一并送检鉴定。研究人员对其中的植物组分与炭屑进行了鉴定，并分离出具备放射性碳定年潜力的物质。最终，针对上述样品中的炭质与炭化植物残体，共获得7份加速器质谱（Accelerator Mass Spectrometry，AMS）放射性碳定年数据。