湖北辽瓦店遗址地层记录的环境变迁与人类活动的关系研究

用XRF和ICP-AES方法分别测试了湖北辽瓦店遗址地层样品的氧化物含量和地球化学元素含量,恢复了遗址地层中夏代文化层、东周文化层和明清文化层记录的环境变化和人类活动特征。结果表明:1)夏代文化层时期,气候温暖湿润,生态环境良好,人类活动与自然环境和谐度高,有原始的手工业活动记录。2)东周时期气候开始进入干旱期,干旱程度在上东周文化层中部逐渐加深(LOI=6.98%),到了上东周文化层顶部气候进入暖湿期。该层Cu含量的异常高值(0.31mg/g)和出土的青铜器表明本文化层反映了青铜社会的繁荣期,而P含量的高值(22.73mg/g)和动物骨屑则反映了该期人们驯养、捕猎动物的普遍性。3)明清时期的气候趋于干凉,明代文化层中部有短暂暖湿期,后又进入冷干期。清代文化层中下部有暖湿特征,之后重新进入干冷期。该层Ca(均值101.5mg/g),Mg(均值60.27mg/g),Zn和Pb的高含量表明遗址曾有过制陶(瓷)业的历史。另外,Mg和Ca含量的高值与耕作区、墙壁灰浆、生活垃圾堆积等人类活动相关。Ca和Mg含量在近现代层逐步升高揭示了人类活动逐渐增强的事实。地层的平均粒径自上东周文化层(<142cm)开始出现振荡,暗示汉江洪水和季节性山洪发生的频率不断增加,表明恶劣环境条件虽然促进了人类生产力水平的提高,但原始生态系统却遭到破坏,人类活动对自然环境的正反馈效应日益凸显。

RELATIONSHIP BETWEEN HUMAN ACTIVITY AND ENVIRONMENT OF THE LIAOWADIAN SITE IN HUBEI PROVINCE

The Liaowadian Site is situated at the northwestern part of Hubei Province,a key region for ancient human activity.Two group data of XRF and ICP-AES for 27 samples from the T0709 exploiting square at the Liaowadian Site were measured.Using principal component analysis（PCA）method,six principal components were chose to be indicators for recovering relationship between human activities and environment.For obtaining comparative comparative analysis,weathering intensity index（（K 2O+Na 2O+CaO）/Al₂O₃）by XRF and loss on ignition（LOI）were introduced to build temperature-precipitation trend curves.According to aforesaid data,the environment and human activity characteristics of the whole profile can be delineated as below: （1） The Xia Dynasty Stage（250～325cm）,warm and moist with well-undergone ecological system.Friendly relationship between human activity and nature appeared a harmonious time.In addition,Pb and Si contents showed that ancient manufacture activity,for instance ceramics-making has started.（2） The Eastern Zhou Stage（120～250cm）.Dry-cool climate started and the driest period was found around the upper layer（LOI=6.98%）of the stage.However,at the end of the stage another warm period appeared.Cu content curve arrives its peak（0.31mg/g）and the large amount of unearthed bronze wares suggested a prevalent bronze-refining and bronze-applying time.Phosphorus content is relative high（22.73mg/g）,implying that animal domestication and hunting might have been common.Meanwhile,the content of silicon is stable,indicating that stone-ware-making was no longer the mainstreaming industry.（3） The Ming and Qing Dynasty Stage（20～120cm）.The main trend of climate was dry and cool,with a short warm period in the middle of Ming Dynasty,afterwards it returned to a long term of drying and cooling similar to that since the middle-late period of the Eastern Zhou Dynasty.Calcite content（mean value 101.5mg/g）and manganese content（mean value,60.27mg/g）as well as high content of Zn and Pb indicate that there had been an enamel manufactory or the like in the vicinity.Moreover,high content of Mg and Ca may be related to human activities such as arable,wall-brushing lime,and daily garbage reserve.The higher and higher contents of Ca and Mg approaching to the level of modern society reveals the more and more enhanced human activity influence intensity.Additionally,mean grain-size of the sediments was characterized by frequent rise and fall,suggesting the high frequency of flood of the Hanjiang River and torrents.All above tells a history of human activity changes along with the natural environment change,and positive feedback effect from nature is prominent.