晋陕峡谷苏家岭和清水川口旧石器地点黄土地层释光年代与古环境

在黄河中游晋陕峡谷地区发现了多处旧石器遗存，但是，这些重要的遗址点大多缺乏年代约束。新发现的苏家岭和清水川口旧石器地点位于陕西一侧黄河二、三级阶地上，黄土堆积中出土的石器类型以"石核-石片技术"组合为主要特征。本研究采集了苏家岭（黄土堆积厚度17.1 m）和清水川口（黄土堆积厚度4.7 m）共14个光释光样品，采用石英单片再生剂量法（SAR-OSL）和钾长石红外后释光法（pIR200IR290）测定了两个遗址点黄土序列的年代，同时测试了沉积物样品的粒度和磁化率。结果表明，两处沉积物主体均为典型的风成黄土。石英SAR-OSL年龄与钾长石pIR200IR290年龄在25~50 ka有很好的对应关系，钾长石年龄与S1古土壤的预期年龄（MIS5）相一致。苏家岭出土的石器所在地层年代范围为25~76 ka，洪积层的石核年代在76~95 ka间；清水川口出土的石器年代范围为31~42 ka。地层特征、磁化率和粒度证据表明，在晚更新世间冰阶和末次间冰期末期，晋陕峡谷地区相对暖湿的气候条件利于远古人类生存；同时，黄土高原南部苏家岭与北部清水川口的古环境存在区域的差异。苏家岭和清水川口地点出土的"石核-石片技术"组合表明，晚更新世古人类在中国北方广阔的区域活动，中国中部是晚更新世人类栖居的良好场所。

Optically stimulated luminescence dating of the loess-Paleolithic sites and paleoenvironment variations at Sujialing and Qingshuichuankou in Jin-Shaan Canyon,northern and central China

Numerous Paleolithic artifacts have been discovered in the Jin-Shaan Canyon area of middle reaches of Yellow River, Northern and Central China, whereas chronological constraints on these Paleolithic sites are still lacked. The Sujialing (SJL: 35°48'46.58″N, 110°33'28.12″E) and Qingshuichuankou (QSCK: 39°10'35.52″N, 111°09'44.41″E) loess-Paleolithic sites were recently discovered on the right bank of Yellow River's second and third terraces. The unique in-situ artifacts were found in loess deposits are primarily characterized by the combination of cores and flakes technology. These discoveries have provided an unprecedented insight into early human adaption and dispersals in the middle branch of Yellow River, Northern China. The SJL profile is approximately 17.1 m thick, while QSCK is around 4.7 m. In this study, 14 samples for optically stimulated luminescence (OSL) were collected and measured using quartz single-aliquot regenerative-dose (SAR-OSL) and K-feldspar post-IR infrared (IR) stimulated luminescence (pIR200IR290) protocols to determine the ages of the loess sequences at the two sites. The quartz SAR-OSL and feldspar pIR200IR290 ages are in good agreement in the range of 25~50 ka. The feldspar ages are consistent with the expected age of S1 palaeosol (MIS 5). The OSL age of the stone tools found at SJL is between 25 ka to 76 ka, with the age of cores discovered in the bottom alluvial layer being between 76 ka to 95 ka. Similarly, the artifacts at QSCK range from 31 ka to 42 ka. Analyses of pedology characteristics, magnetic susceptibility, and grain-size evidence suggest that early human activities were predominantly living in interglacial (or interstadials) periods, a relatively warm and humid climate of Late Pleistocene in Jin-Shaan Canyon area favored survival of early humans; the small flake-core industry unearthed at the two newly discovered Paleolithic sites indicate extensive activities of early humans in the vast northern region of China, with Northern and Central China being a favorable habitat for Late Pleistocene human habitation.