AMS RADIOCARBON DATING OF BONE FROM SITE 25FT376, HUGH BUTLER LAKE (RED WILLOW LAKE), FRONTIER COUNTY, NEBRASKA

Two pieces of bone from site 25FT376 were submitted for AMS radiocarbon dating. This site reflects a remnant of a Holocene terrace on an island in Hugh Butler Lake (Red Willow Lake) in Frontier County, Nebraska. This island is usually under water in the reservoir, but has been exposed during draw-down of the reservoir for repairs to Red Willow Dam. The island surface contains a scatter of bison bone, chipped stone tools, and lithic debitage. Site 25FT376 is believed to reflect an Early Archaic, Logan Creek complex based on similarities of the diagnostic artifacts to those found at the Spring Creek Site, 25FT31, located about 700 meters downstream. Bone from that site yielded a radiocarbon date of 6145 ± 35 RCYBP. The two bone fragments from 25FT376 are expected to also date around 6000 RCYBP.从25FT376遗址提取的两块骨骼样本已提交用于加速器质谱放射性碳定年（AMS，Accelerator Mass Spectrometry）。该遗址坐落于内布拉斯加州边境县休·巴特勒湖（红柳湖，Hugh Butler Lake）内的一座岛屿之上，属于全新世阶地遗存。该岛屿通常处于水库蓄水状态，仅在为维修红柳大坝而进行水库水位泄降时才会露出水面。岛屿地表散布有野牛骨骼、打制石器与石片碎屑。结合该遗址的诊断型文物与下游约700米处的25FT31春溪遗址出土器物的相似性，推测25FT376遗址属于早古风期洛根溪文化复合体。此前对春溪遗址的骨骼样本进行放射性碳定年得到的结果为6145±35 RCYBP（放射性碳年距今年代，Radiocarbon Years Before Present）。据此推测，本次送检的25FT376遗址的两块骨骼碎片的定年结果也将处于约6000 RCYBP的年代区间内。