青海喇家遗址史前灾难成因的探索与辨析

周强, 张玉柱

Exploration and analysis of the reasons for pre-historical catastrophes in the Lajia Ruins, Qinghai Province

Qiang ZHOU, Yuzhu ZHANG

表3 喇家遗址红色粘土层(XLJ)、岗沟源沉积物(GGY)与黄河古洪水沉积层(JSX)粒度分析

Tab. 3 Grain-size distribution in the sediment samples from the conglomerated red clay in the Lajia Ruins, the gully deposit at the Ganggou gulley emerges, and the palaeoflood deposit in the Jishixia Gorge on the upper Yellow River

样品名称 粘粒(μm, %) 细粉沙(μm, %) 粗粉沙(μm, %) 沙粒(μm, %) 中值(μm) 平均(μm) 偏态 峰态 分选系数 XLJ 28.46 56.64 14.89 0.01 4.70 6.97 0.15 0.95 1.33 GGY 28.07 57.39 14.54 0.00 4.87 7.00 0.16 0.92 1.33 JSX 12.50 71.30 16.20 0.00 7.06 6.35 0.08 1.06 0.90