中文摘要：

通过对位于江汉平原北部石家河古城内谭家岭遗址地层孢粉、碳氮地球化学和磁化率代用指标的综合分析表明,石家河文化早期（4.6—4.4 ka BP）,孢粉浓度较高且种类多,特别是喜暖湿的孢粉科属含量较大,植被覆盖较好,说明遗址及周边地区受人类活动干扰较少;TOC、TN和C/N偏高,δ^（13）C_（org）偏低,表明当时以C_3植物为主,气候较为温暖湿润;该时期遗址区域可能积水较多,磁化率值总体较低,发生过水域面积增大但持续时间不长的变化,石家河古城在防御洪水及外敌入侵方面发挥了较大作用。石家河文化中晚期（4.4—4.0 ka BP）,孢粉种类和浓度减小,TOC、TN和C/N也持续减小,δ^（13）C_（org）则偏高,气候凉干,降水减少,遗址区域积水减少并逐渐演变成古人的居住用地,受人类活动影响磁化率值明显增高;由于河湖、地下水位下降,石家河古城防御洪水与外侵的功能消失并逐渐废弃。4.2 ka BP前后气候持续凉干,极端灾害事件频繁发生,影响了当地农业和渔猎业的发展,使得石家河文化发展停滞,这是导致本区石家河文化衰落的重要环境因素。

英文摘要：

Background, aim, and scope The middle Yangtze River basin is a developing and fl ourishing area of the Neolithic cultures, as revealed by abundant archaeological sites in the Jianghan Plain. The Shijiahe Culture is representative of an advanced stage in the Neolithic Age, and archaeological remains reflect the features of native culture in the Jianghan Plain. The Shijiahe Culture fully flourished in its early and middle stages, but it deteriorated around 4.2 ka BP. Some topics of the cause of this cultural deterioration such as the war, disaster, climatic events, southward migration, and abandonment of the ancient city are still under debate. Also, no systematic analysis was conducted throughout the method of archaeological stratigraphy. Therefore, the Tanjialing Neolithic Site during the Shijiahe cultural period provides a good opportunity and material to examine the relationship between anthropogenic impact and environmental dynamics by palynomorph-TOC-TN-δ~（13）Corg-magnetic susceptibility analysis, owing to its well chronological control, rich organic sediment, and unique archaeological fi ndings. This study is highly necessary to better understand interaction between human and nature in this special historical period. Materials and methods The Shijiahe ancient city is located in the northwest of Shihe Town, Tianmen City, Hubei Province, and geographically lies in the north-central Jianghan Plain. The terrain is higher in the northwest, and the elevation is 33 — 40 m above sea level. The Tanjialing Neolithic Site is situated in the center of Shijiahe ancient city. An archaeological sedimentary profi le, in the south wall of T0620 from the site, was examined for pollen, TOC, TN, δ~（13）Corg and magnetic susceptibility. The profi le is 330 cm in thickness and divided into 9 lithological horizons. 28 samples were collected in the 9th layer, 22 samples in the cultural layers for palynological analysis, and 97 samples for TOC, TN, δ~（13）Corg and magnetic susceptibility analysis. The date of the whol