仰韶村遗址黏土矿物组成特征及古气候演变

Clay Mineral Composition and Paleoclimate Evolution in Yangshao Village Site

在仰韶村遗址内分别选取受到古人类活动干扰的土壤剖面(简称文化剖面)和未受到古人类活动干扰的土壤剖面(简称自然剖面),通过两剖面的黏土矿物类型以及测年数据,还原该遗址全新世以来的气候变化,并对古人类活动内容进行了推测。根据自然剖面的黏土矿物类型判断,该遗址10~6.9 ka B.P.增温增湿至稳定,6.9~5.6 ka B.P.气候出现波动,总体向干旱转折,5.6~4 ka B.P.气候变为干冷,4 ka B.P.之后气候进一步变干冷。通过比较,受古人类活动干扰,黏土矿物类型变得简单,并在某一文化时期出现高岭石,推测古人类用黏粒含量高的土壤进行地面铺设,便于塑性和硬化以作为居住地面。

A soil profile disturbed by paleo-human activities(referred to as cultural profile) and a soil profile undisturbed by paleo-human activities(referred to as natural profile) were selected from the Yangshao Village site.Based on clay minerals in natural sections and dating data, the climatic changes since Holocene at the site were reduced, and the differences of clay minerals between the two sites were compared to infer the contents of paleo-human activities. Soil temperature and humidity were increased to stable levels from 10 ka to 6.9 ka B.P. From6.9 ka to 5.6 ka B.P., the climate fluctuated and turned to drought in general. From 5.6 to 4 ka B.P., the climate became dry and cold. After 4 ka B.P., the climate became further dryer and colder. By comparison, clay mineral types became simple due to the disturbance of ancient human activities. Kaolinite appeared in a certain cultural period. It is speculated that ancient humans used clay-rich soil to lay the ground, which was plastic and hardened for residential floor.