青海喇家遗址史前灾难成因的探索与辨析

在黄河上游官亭盆地的考古发掘中喇家史前灾难遗址的发现让人震惊,其灾难的成因是近年来人们争论的焦点。本文从地球科学的视角入手,在详细野外考察的基础上,利用第四纪地质地貌学、沉积学、古洪水水文学等多学科交叉的研究方法,对当前关于喇家遗址史前聚落毁灭原因的各种观点进行科学辨析,尤其是对剖面中红色粘土层与喇家遗址北部大红山脚下的岗沟源区沉积物及其上游积石峡黄河古洪水滞流沉积层的对比研究,结果显示：在距今3950年前,伴随着强烈地震发生了暴雨山洪,源自于北侧谷坡大红山地区的大规模泥流,沿着岗沟、吕家沟倾泻而下,彻底的掩埋毁灭了这个重要的古村落,造就了喇家史前灾难遗址。

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

Archaeological excavations have exposed a shocking picture of the prehistorical calamities in the Lajia Ruins in the Guanting Basin along the Yellow River. The destruction reasons has been a hot and focus issue in recent years. Geological records of the major disasters in relation to the devastation of this prehistorical settlement were investigated by detailed field observations, sedimentological analysis and optically stimulated luminescence (OSL) and ¹⁴C dating. More importantly, we made a comparative study of the conglomerated red clay, the gully deposit at the foot of the Great Red Hills where the Ganggou gullies emerge onto the Guanting Basin, and the palaeoflood deposit of the Yellow River in the barrier lake in the Jishixia. The results show that at ca. 3950 a BP, immediately followed by a major earthquake, the settlement was overtaken by immense mudflows coming along the tributary gullies from the hillsides behind. The enormous mudflows suddenly buried and destroyed the dwellings, which led to the prehistorical calamities in the Lajia Ruins. These results are of important implications in understanding the prehistorical environmental change in the environmentally sensitive zones over the world. It has very important reference value for the further studying of man-land relationship.