陕西蓝田全新世黄土AMS-^(14)C测年与环境变迁

AMS-^(14)C Dating of the Holocene Loess Sequence at Lantian,Shaanxi and Reflected Environmental Change

加速器质谱计14C(AMS-14C)测年技术具有精度高、速度快以及样品需求量少的特点,已广泛用于晚第四纪和新石器时期的断代研究。通过对蓝田县新街遗址旁的全新世黄土-古土壤序列进行AMS-14C测年,并利用贝叶斯分析方法,建立了该地层序列的年代学框架。结合新街遗址考察、黄土-古土壤地层划分、磁化率测量和孢粉分析,表明马兰黄土晚期气候偏凉干,进入全新世时期气候转暖,仰韶时期温暖湿润,龙山时期气候暖偏干,新黄土堆积时期气候转干冷。

AMS-^14C dating provides a new way in archaeology studies because of its high precision and speed and applicability in micro-sample dating. It is widely used in late Quaternary and Neolithic archaeological research. Based on AMS-^14C dating of loess-paleosol sequence of the Xinjie profile at Lantian County of Shaanxi Province, the archaeological chronology of this sequence was obtained by using Bayesian method. Combining the stratigraphic sequence, magnetic susceptibility and pollen analysis, we got the conclusion that the weather was dry and cold during Malan loess period, and warm in Holocene, humid and warm in Yangshao period, dry and warm in Longshan period, dry and cold in recent Loess forming period.