【作者】 李枫；

【导师】 朱诚；

【作者基本信息】 南京大学 ， 自然地理学， 2014， 博士

【摘要】 江汉平原是由长江及其支流汉江汇合而成的典型河积-湖积平原,是能显著反映全球-区域尺度自然系统变化和区域-地方人地关系长期相互作用的典型区域。本研究就是在全面考察江汉平原地质构造和地貌特征的基础上,通过多指标的综合集成分析,重建江汉平原5.5～3.4kyr BP古环境变化过程；同时,借助GIS技术手段分析新石器时代中晚期区域内考古遗址时空分布和典型聚落形态变化。以此为切入点进一步探讨江汉平原5.5～3.4kyr BP地理环境背景变化的机制及其对考古文化演替的影响,剖析考古文化断层的成因,实现对区域史前人地关系动态变化科学问题的解答。通过对江汉平原JZ-2010剖面沉积物中孢粉、总有机碳、总氮、有机碳同位素、元素地球化学性质、磁化率以及粒度等在内的多项环境替代指标的分析,结合野外考察确认的地貌条件及沉积特征,可知剖面记录的5.5～3.4kyr BP区域环境整体属温暖湿润的气候条件,但随时间推移不稳定性增强,并呈现降温和变干的趋势。其时湖泊发育,湖洼地外河流及地表径流带入的泥沙极少,沉积速率很小,沉积以粘土质粉砂为主体。周围为北亚热带针阔叶混交林草地或中亚热带常绿落叶阔叶混交森林草地植被景观。各项指标记录的4.4～4.2kyr BP气候快速显著变干,明确响应了全球变化的4.2kyr事件。JZ-2010剖面记录与典型考古遗址探方及区域代表性研究成果的综合对比,说明5.5-3.4kyr BP江汉平原的环境变化具有比较一致的过程,都经历了全新世大暖期衰退期不稳定的温湿阶段(5.5～5.1kyr BP)-适宜的暖湿阶段(5.1～4.5kyr BP)-温暖的干旱化阶段(4.5-4.2kyr BP)-温度下降干湿波动阶段(4.2～3.7kyr BP)-稳定但减弱的暖湿阶段(3.7～3.4kyr BP)。同时也包含了4.9-4.6kyr BP和4.1～3.8kyr BP两个洪水频发的时期。江汉平原独特的地理位置,使得其对以低纬过程为主导次级驱动的东亚季风变化产生明确响应。自白垩纪以来即持续下沉且沉降量大于沉积量的构造特点,东北方、北方和西方为山地包围而面向东南方倾斜开放的箕斗状地形,都对江汉平原中全新世以来区域气候环境变化产生了深刻影响。对江汉平原大溪(6.5～5.1kyr BP)、油子岭(5.9～5.1kyr BP)、屈家岭(5.1～4.5kyr BP)及石家河(4.5～4.0kyr BP)等新石器时代考古文化遗址时空分布变化和典型聚落形态演化的分析表明,各期文化遗址及史前古城均集中分布于江汉平原北部和西部边缘地带,海拔30～100m范围内的山前岗地和河流低阶地地貌部位,极大程度地受制于江汉平原新构造运动特点和从边缘向中心海拔递减的环形分布地貌特征。在此基础上对考古文化序列与区域地理背景的探讨显示,江汉平原独特的地理位置和构造地形共同效应形成的良好生态优势,使其在全球变化5.3kyrBP事件期间未受显著影响,从而大溪文化-油子岭文化获得较大发展；5.3kyr BP之后油子岭文化的迅速扩张和随后屈家岭文化对长江中游的统一,亦得益于汉东地区通达性极强的地理区位,以及面积较大、河流湖泊发育、自然资源丰富多样的大洪山山前岗地所提供的史前人类理想栖息地。对江汉平原5.5～3.4kyr BP气候环境变化对新石器时代晚期各考古文化特点及演替影响的讨论,揭示了环境变化与史前人类活动两者关系随时间历程的动态变化。持续的适宜的温暖湿润气候和良好的生态环境促进了屈家岭文化的繁荣,人口增长和聚落规模的扩大逐渐形成对区域环境和资源的压力；4.5kyr BP后气候变化导致的环境退化及资源限制,客观上促使了原始社会形态高度密集且组织性增强,继续推动着石家河文化的发展；4.2kyr事件的干旱效应和随后的洪水期摧毁了史前社会的原始稻作农业经济基础,石家河文化于晚期急剧萎缩、覆灭并形成文化断层。江汉平原5.5～3.4kyr BP人地关系地域系统主要由自然地理环境子系统、人文地理环境子系统和人地调控子系统三者构成,其组成要素在空间地域和时间进程上相互重叠或交错,彼此之间通过物质、能量的交流,相互渗透、相互制约和相互作用而构成一个有机整体。随着时间的进程,江汉平原人地系统地理环境与人类活动的动态关系变化依次表现为协调成长型、冲突脆弱型和危机破坏型,考古文化从成长、扩张、繁荣转而为衰退、消亡和湮灭。更多还原

【Abstract】 In recent years, all too often it seems as though our pursuit of economic security or improved station in life leads us to compromise or even undermine the quality of the natural environment, further, strengthen the conflict of human and nature. Until recently, however, people have realized that our future and well-being depending on the normal and functional earth system, thus, deepen studies and comprehensive insight of the human-earth interaction is in sore need.The Jianghan Plain, suited in Central China, is a typical floodplain of the middle Yangtze and the Hanjiang River composed of many interchannel depressions, with a variety of complicated geological factors, including sedimentary provenance, hydrodynamic conditions, microrelief of rivers and lakes, climate, and sedimentary environment. Its main body is located in the transitional zone of the second to third step of the so-called "three-step ladders" Chinese topography, therefore, a unique spatial location. Controlled by the East Asia monsoonal climate, both temperature and precipitation of the plain exhibit remarkable seasonal variability. As important national commodity grain production base, key industry construction area and irreplaceable transportation junction, the Jianghan Plain is now experiencing high speed economic-social modernization while, consciously or unconsciously, strengthening more and more pressure on the environment and ecosystem which have severely affect the regional sustainable development. Archaeological research has demonstrated that as far back as the Palaeolithic Age humans had been thriving here. Around5300years ago, Qujialing Culture whose core area was in the north-central of the Jianghan Plain broken the southern system and northern system parallel pattern and unified the Neolithic Culture in the middle reaches of the Yangtze Rivers. This marks the beginning of the early civilization in China from the prehistoric culture, unfortunately, dramatically declined in the late period of Shijiahe Culture and following with the Post-Shijiahe Culture a prehistoric culture hiatus of hundreds of years long in the Jianghan plain. Hence, the Jianghan Plain is a typical area to depict the global to regional-scale natural system changes and long-term regional to local scale human-earth interactions. On the basis of investigation and studies of the tectonic and geomorphologic conditions, this paper reconstructs the geographic environment changes during5.5-3.4kyr BP using multi-proxies synthesis integrating method. Meanwhile, the spatial-temporal pattern of changes of the different cultural periods, along with the transformations of the typical prehistoric settlements, were analyzed and compared by means of GIS or spatial analysis. Further, this study discuss the mechanism of the geographic environment changes and the relationships between the archaeological culture evolutions and the geographic environment changes, ultimately, solving the key scientific question which is the structure of the regional man-earth system of the Jianghan Plan, as well as how the system components and elements are dynamically related in different spatial-temporal process during5.5-3.4kyr BP.Based on the time sequence of the JZ-2010profile derived from AMS14C dating and the comprehensive analyses of the multiple alternative environmental indicators, such as the spore-pollen assembles, the TOC, TN,δ13Corg values, the geochemical components, the magnetic susceptibility and the granularity parameters, combining geomorphic conditions and sedimentary features, the palaeoenvironment of the Jianghan Plain during5.5-3.4kyr BP was generally warm and humid, however, with enhancing instability and the trend of drier and colder. Over the time, the lakes expanded with a low deposition rate as the result of very little sediments were brought into the basin by surface runoff, consequently formed clayey silt. The vegetation distribution was mainly the subtropical evergreen needleleaf-broadleaf and mixed forest and woodland. All the environmental indicators recorded severe drought during approximately4.4-4.2kyr BP, apparently responding the4.2kyr event. The integrated of the JZ-2010records, the results of typical archaeological rectangular units, as well as the selected previous research works demonstrated five stages of the climate and environmental changes of the Jianghan Plain from5.5to3.4kyr BP: unstable warm-wet stage (5.5-5.1kyr BP) in the period of post Holocene Thermal Maximum, appropriate warm-humid stage (5.1-4.5kyr BP), warm and dry stage (4.5-4.2kyr BP), slightly warm and wet-dry seesawing stage (4.2-3.7kyr BP), stable but weaken warm-humid stage (3.7-3.4kyr BP). Moreover, two high frequency flood periods events are manifested during4.9-4.6kyr BP and4.1-3.8kyr BP.Comparative analyses revealed that the impacts of regional topography that sustained tectonic subsidence since the Cretaceous, adding its southeast tilt, a dustpan-shape surrounded by mountains in the west, northwest and north, opened the Jianghan Plain to the summer monsoon, has resulted distinctive environment changes and regional responses to the global changes since the mid-Holocene.Archaeological studies have identified the Neolithic cultural sequence in the Jianghan Plain during5.5-3.4kyr BP which consist of Daxi Culture (6.5-5.1kyr BP)/Youziling Culture (5.9-5.1kyr BP), Qujialing Culture (5.1-4.5kyr BP) and Shijiahe Culture (4.5-4.0kyr BP). Using GIS combined with archaeological and geographic data, this dissertation presented that most of the related Neolithic sites are concentrated in the western and northern edge zone, with an altitude of30-100m, on the lower terraces of rivers and piedmont downlands, demonstrating the significant effects of the regional tectonic features, as well as the landform featured with latitude decreasing from edge to centre. Owing to its geographic locality and complexity, the Jianghan Plain showed pretty well climate conditions and ecological advantages that witness the development of the Daxi-Youziling Culture. After5.3kyr BP, the rapid expansion of the Youziling and the following the Qujialing’s unity of the prehistoric culture in the middle reaches of the Yangtze were attributed to its unique geographic location of the eastern area of Hanjiang River (the Handong Area). Comparing with the other areas in the Jianghan Plain, the Handong Area possesses stronger accessibility, lager land with rivers and lakes, more abundant natural recourse, all combining made the Dahong Mount piedmont downland an ideal habitat for prehistoric human being.Discussion on the climatic and environmental changes and Neolithic Cultures evolutions in the Jianghan Plain during5.5-3.4kyr BP revealed their dynamic correlation. Continuous appropriate warm-humid climate and well ecologic environment promoted the flourishing of the Qujialing Culture, however, increasing population and expanding settlement scale gradually enhanced the pressure on the regional environment and resources. From approximately4.5kyr BP, the environmental recession and resources limited urged a more tighten primitive society structure and highly organization, objectively pushing the development of the Shijiahe Culture. The virtuous interaction of human and nature was broken by the4.2kyr event whose severe drought and following floods eroded the economic foundation on the basis of rice-cultivation agriculture, the Shijiahe Culture dramatically withered and left a culture hiatus. The dynamic interrelation of the Jianghan Plain human-earth system in different spatial-temporal process over the5.5-3.4kyr BP could be summarized as three types:harmonious growing type, conflicting fragile type and critical destructive type, which was corresponding to the archaeological cultures flourishing, shrinking and died out at last.更多还原