EXAMINATION OF SEDIMENT TO RECOVER BONE FOR RADIOCARBON ANALYSIS FROM A HIGH SHORE LINE OF GLACIAL LAKE GREAT FALLS, MONTANA

Sediments collected from a high shore line of Glacial Lake Great Falls at an elevation of 3860 feet were processed to separate bones to submit for identification and radiocarbon analysis (Table 1). This area is near the modern Missouri River. The Pleistocene lake silts, overlain by Pleistocene shore lines, contained bone representing animals that lived along the shore of this lake during the Pleistocene era. These lacustrine sediments contained several bone fragments, many of which appear to represent rodents. The bones were separated into various types (Table 2) to facilitate identification prior to submission for radiocarbon analysis.研究人员从海拔3860英尺的大瀑布冰川湖（Glacial Lake Great Falls）高岸线处采集沉积物，经分选处理提取骨骼样品，用于物种鉴定与放射性碳测年分析（radiocarbon analysis，见表1）。该区域毗邻现今密苏里河（Missouri River）。覆于更新世（Pleistocene）湖岸线之下的更新世湖相粉砂沉积物中，保存有更新世时期栖息于该湖岸周边的动物骨骼遗存。上述湖相沉积物（lacustrine sediments）中共发现多块骨骼碎片，其中多数疑似属于啮齿类（rodents）。为便于后续物种鉴定，在送检开展放射性碳测年分析前，研究人员已将骨骼按类别进行分组（见表2）。