【作者】 张广胜；

【导师】 王心源；

【作者基本信息】 安徽师范大学 ， 自然地理学， 2007， 硕士

【摘要】 巢湖流域是远古人类重要的活动区域,也是文化兴替频繁的地方。自新石器时代以来,巢湖流域的人们对自然环境的利用体现了很高的智慧,创造出了灿烂的文明。探讨该区域全新世早中期以来区域自然环境的演变,对于揭示古地理环境的特征,古人类活动状况,区域文化的更替等都有一定的借鉴意义。同时也为指导区域环境考古,加快区域的可持续发展奠定基础。通过对采自巢湖西湖区的湖泊柱样沉积物的年代学、孢粉学等的分析,并辅助于粒度、磁化率等气候环境代用指标的分析和研究,结合相邻区域环境演化的对比和区域人类活动的历史文献记载,重建了研究区域9870cal.aB.P.以来的环境演变序列。主要结论如下:1在巢湖西湖区采集的490cm的湖泊沉积物柱样主要为青灰色泥层,部分为青灰色泥夹细砂层为主。AMS14C测年所得的7个年代数据分析表明,该沉积物柱样为9870cal.aB.P.以来的沉积。2多环境代用指标分析表明,研究区域9870cal.aB.P.以来的环境特征如下:1)早中全新世的9870-6040cal.aB.P.期间,环境总体上为温暖湿润,巢湖处于高水位,湖面扩张;8120cal.aB.P.左右开始的8120-7700cal.aB.P.期间气候开始变干,变化较为显著,可能对应一个冷干期,温度和湿度较前一段时期有所下降;7700-6030cal.aB.P.左右研究区气候开始向温和湿润的气候变化。其中9600cal.aB.P.,9240cal.aB.P.和6160cal.aB.P.前后可能对应该时期的三次较大的温暖湿润期。2)中晚全新世的6040-4860cal.aB.P.期间,环境由前一时期的温暖湿润向着更加温暖湿润转化。5900cal.aB.P.前后可能对应一次特别温暖湿润期;5650-5500cal.aB.P.前后对应着一段干旱时期;5550-5400cal.aB.P.期间更加温暖湿润,降雨量丰富;5400-4860cal.aB.P.左右开始向干旱、降雨量减小、湖面收缩转化。3)中晚全新世的4860-2170cal.aB.P.期间,气温逐渐降低,湿度也下降,巢湖流域处于冷干时期。3900cal.aB.P.前后,多指标的波动分析,可能对应一次大的干旱时期,一直持续到2980cal.aB.P.前后。后期的2980-2170cal.aB.P.,环境整体上继续向着干旱转化,湖面继续收缩。2170cal.aB.P.左右可能是巢湖历史上湖面最小的一个时期,巢湖湖盆局部地区出露。4)晚全新世的2170-1040cal.aB.P.期间,巢湖流域温暖湿润的时期,降雨量加大,湖面开始再次扩张,气候宜居,巢湖流域也受到人类活动的强烈影响。2170cal.aB.P.左右各种指标的急剧变化,综合研究可能发生区域急剧的转温暖湿润时期,湖水涨起,湖面扩大,并可能造成一次洪灾。5)晚全新世的1040-200cal.aB.P.期间,总体上气候较温暖潮湿,湖面逐渐扩张。其中1040-750cal.aB.P.为气候向温暖湿润转化;750-620cal.aB.P.环境比较温暖湿润;620-200cal.aB.P.环境较为干旱,湖盆不断缩小,湖面不断收缩,是巢湖淤积较为严重的一个时期。人类生产活动的加强也是导致该时期沉积物环境指标变化的重要因素。6)最近200cal.aB.P.以来,巢湖流域气候仍处于温暖湿润阶段。湖泊有机质含量增加,磁化率出现低值。在大约120cal.aB.P.前后,粒度出现一个极高值,可能与人类大规模的开发活动有关。3从湖泊沉积物环境代用指标记录的巢湖流域全新世9870cal.aB.P.以来的气候和环境演变信息可以看出,一方面巢湖区域环境演变受到全球环境变化的影响,是区域环境变化对全球环境变化的响应;另外一方面,由于巢湖独特的地理位置,和区域自然地理背景,所处的构造活动带,所处的流域特征等,都使该区域环境变化有了更多的复杂性,环境演变具有区域特征。同时,湖泊沉积物不仅记录了中晚全新世巢湖流域环境演化,也记录了人类活动对沉积环境的影响。更多还原

【Abstract】 The Chaohu Lake basin was humanity’s important active area in the ancient times. It also was the place that cultural prosperity and decline frequently. People of Chaohu Lake basin have manifested the very high wisdom to the use of natural environment since the New Stone Age. They have created the advanced civilization. Discussing natural environment evolution in this region at early and middle stage of Holocene is very useful to the Peleoenvironment, the human activities, the region culture change and so on all has the certain model significance. Simultaneously, it also can make the foundation for instructing the region environmental archaeology and speeding up the regional sustainable development.Based on the environmental history record which through to gathering lake sediment column type chronology in the west Chaohu Lake and the analysis of spore-pollen, the research of grain-size and the magnetic susceptibility, it has been reconstructed the regional environment evolution sequence since 9870cal.aB.P.. Main conclusion as follows:1 The West Chaohu Lake District 490cm lake sediment column type mainly for turquoise the putty level, partially clamps the thin sand body for green-gray color the putty primarily. 7 AMS14C dating data indicated that lake sediment is the lake sediment since 9870cal.aB.P.2 Multi-proxy index analysis shows the following character of climate and environmental changes since 9870cal.aB.P..1) In about 9870-6040cal.aB.P. period, it is warm and wet, Chaohu Lake is in the high water mark, it is expansion for lake surface; About 8,120-7700cal.aB.P. period,the climate starts to change and possibly corresponds cold-dry period, the temperature and the humidity compares the preceding section of times to have the drop ; About 7,700-6030cal.aB.P. the area climate starts to the warm and wet climatic change. 9600cal.aB.P., around 9240cal.aB.P. and 6160cal.aB.P. possibly were the warm and wet time.2) In about 6040-4860cal.aB.P.period, the region environment was warm and wet. Around 5900cal.aB.P.,it possibly corresponds a time of specially warm and wet time.Around 5650-5500cal.aB.P.,it is corresponding a section of dry periods; 5550-5400cal.aB.P. period,it was warmer and wetter,the rainfall is rich. About 5,400 - 4860cal.aB.P.it starts to the drought, the rainfall to reduce.3) In about 4860-2170cal.aB.P.period,the temperature gradually reduces, and the humidity also drops, it was a cold-dry period in Chaohu Lake basin. Around 3900cal.aB.P., proxy index and so on deposit granularity and magnetic susceptibility appears a time of bigger undulation, reflected possible to correspond a time of dry period. The environment undulation probably continues to around 2980cal.aB.P.. This stage later period 2,980-2170cal.aB.P., in the environment whole continues to the arid transformation, lake surface continue to contract. About 2170cal.aB.P.,it possibly is in the history of Chaohu Lake lake surface a smallest time, Chaohu Lake trough and local area possibly appears above the water surface.4) In about 2170-1040cal.aB.P.period , it is Chaohu Lake basin warm-wet time, the climate is suitable the humanity to live, lake surface starts to expand once more. This issue of Chaohu Lake basin also comes under the intense influence which the human moves. About 2170cal.aB.P. each kind of proxy index rapid change, the synthetic study that is possible the region suddenly to correspond to transfer warm and wet, the lake high water gets up, the area expands, and it possibly creates a time of flood disaster.5) In about 1040-200cal.aB.P.period,multi-proxy indexs reflection overall the climate warmer is wet. In the granularity overall assumes the tendency which reduces, reflected the Lake Chaohu basin warm continues to be wet, lake surface gradually expanded transforms, has established the modern Lake Chaohu lake trough shape. 1,040-750cal.aB.P. is the warm and wet time; 750-620cal.aB.P. environment is warm and wet; 620-200cal.aB.P. environment is arid, lake trough unceasingly reduces, lake surface unceasingly contracts the stage,possibly is Lake Chaohu silts up a more serious time. The humanity produces the activity to strengthen also is causes this time deposit environment proxy index change the important attributes.6) Since recent 200cal.aB.P., the Lake Chaohu basin climate is still the warm and wet stage. The lake organic content increases,the magnetic susceptibility appears the low value. Around 120cal.aB.P., the granularity appears an extremely high value, is possible and humanity’s large-scale development operation concerns.3 The article analyzes environment changes recorded by lake sediment from the Chaohu Lake basin since 9870cal.aB.P..On the one hand the regional environment evolution is a part of the global environment changes,it is influenced by the whole world environmental changes.So it is the response to the whole world environment changes. On the other hand, as a result of the Chaohu Lake unique geographical position, with the region physical geography background, the structure mobile belt which locates, locates the basin characteristic and so on, all was changes the regional environmental changes to have more complexity, therefore the environment evolution had the region characteristic. At the same time,since former-middle Holocene Chaohu Lake basin environment evolves,it also has been influenced by the partial humanity moves.更多还原