【作者】 舒强；

【导师】 李吉均；

【作者基本信息】 南京师范大学 ， 自然地理学， 2004， 博士

【摘要】 本文是在国家自然科学基金委员会主任基金《长江地貌发育与流域系统演化研究》课题的工作基础上，首次在东部典型季风区域内以环境变化研究为目的的较长时间尺度的研究。利用测井曲线、粒度分析指标，并结合岩性描述结果，对研究区域的沉积地层和沉积环境进行了分析与重建；利用粒度分析、色度测量、碳酸盐含量分析、磁化率测量、孢粉记录等环境代用指标，初步建立了苏北盆地近3Ma以来的环境演变过程与特征，为随后进一步开展工作，建立东部地区新生代晚期以来的环境变化序列提供了前期研究基础。 根据岩性描述、自然伽玛和自然电位测井曲线，以及粒度分析结果，对研究区内的沉积环境进行了研究，共划分出以下几个大的沉积环境时段：350～296.1m间为河流—湖泊交替的沉积环境；296.1～254.1m间为湖泊沉积环境；254.1～230.1m间为渐变性的河流相沉积环境；230.1～156.2m间为较长时段的湖泊沉积环境过程，在期间曾出现过短暂的河流沉积环境过程；156.2～102.8m间为河湖交替沉积环境；102.8～48.78m间为湖泊沉积环境；48.78～38.21m间为沼泽沉积环境；38.21～11.62m间为湖滨浅水沉积环境；11.62～0m间为湖沼相沉积环境。 在苏北盆地兴化地区近3.0Ma的沉积发展过程中，可能还发生了多次的大小不一的构造活动，其中在深度254～230m(2.32～2.13Ma)间发生的一次构造运动是其中最大的一次，此次构造运动的发生，不仅导致了兴化地区的大量含砾砂层的出现，而且可能导致了苏北盆地内部水系的调整，致使到达兴化地区的沉积物来源发生了变化。 兴化钻孔多环境代用指标记录了苏北盆地近3.0Ma的气候环境演变过程与特征。在近3Ma的时间中，苏北盆地兴化地区的气候环境经历了以下几个演化阶段：3.26～2.68Ma期间的相对湿润气候期：2.68～2.32Ma期间的相对干旱气候期；2.32～2.13Ma期间的相对湿润气候期；2.13～1.50Ma期间的相对干旱气候期，中部出现短时间的湿润波动：1.50～1.00期间的相对湿润气候期；1.00～0Ma期间为干湿分异极为明显的时段，期间干湿波动频繁，共记录到了6～7次较为明显的干湿波动旋回。苏北盆地兴化钻孔近3Ma环境变化记录研究 研究结果还表明近3.OMa来，中国东部典型季风区域的气候环境发生了两次大的变化。2.26一2.16Ma时段是中国典型季风气候形成的转折时期，在此时段之前苏北盆地沉积物记录的气候某些方面尚未完全脱离上新世的格局，具有稀树草原气候的某些特征，到2.16Ma后苏北盆地才具有高温高湿的东亚季风区的典型特征。再一次是在约0.gMa以来的时段内，冰期与间冰期的分异较为明显，有着显著的冰期与间冰期过程。 兴化钻孔所揭示的近3Ma以来的气候干湿变化与深海氧同位素和黄土高原记录之间有着较好的可比性。尤其是布容世以来的气候环境变化过程，兴化钻孔揭示的结果不仅与区内的风成沉积之间可以很好的对比，而且与北方黄土高原与深海氧同位素记录之间有着良好的吻合性。这说明了我国东部地区的气候环境变化不仅具有显著的区域性特征，而且具有全球气候变化一致性特征。 通过东部地区内上新世末期以来的气候环境变化特征的对比发现，在东部地区内，由于各地所处的地理位置的差异性等因素，东部地区内各地出现现代典型季风气候特征的时间有一定的差异。这种差异性在一定程度上说明了，影响东部地区的季风气候在第四纪初期并不强大，其控制区域还相对有限，而随着季风的加强，季风能够影响到的区域扩大，到早更新世末期，季风气候影响到整个东部地区。 研究还表明，我国东部地区的气候环境变化特征与青藏高原隆升的阶段性、西太平洋暖池、黑潮之间有着密切的关系。青藏高原的隆升、西太平洋暖池、黑潮的形成与发展都对东亚季风系统有着重要的影响。更多还原

【Abstract】 Supported by the NSFC director fund "Research on physiognomy development and the drainage area evolution of Yangtse River basin", for the first time, we have done much research work on long time-scale palaeoenvironmental changes of Eastern China typical monsoon area. The sediment stratum and environment was analyzed and reconstructed by GR curve, granularity index and lithology characterization. By multi-proxy analysis, such as granularity, chroma, carbonate content, susceptibility, sporo-pollen assemblages, etc, we have constructed the palaeoenvironmental change processes during the past 3 Ma of northern Jiangsu basin, and which will provide a foundation for constructing the palaeoenvironmental change sequences of Eastern China since Late Cenozoic.The results of lithology characterization, GR curve and granularity analysis indicate that, the sediment condition in Xinghua has experienced several alternation. The research results are as follows, 350~296.1m, deposit of fluvial-lacustrine alternative facies; 296.1 ~ 254.1m, deposit of lacustrine facies; 254.1~230.1m, deposit of fluvial facies; 230.1m~156.2m, mainly deposit of lacustrine facies, in which there is a short-term deposit of fluvial facies; 156.2m~102.8m, deposit of fluvial-lacustrine alternative facies; 102.8m~48.78m, deposit of lacustrine facies; 48.78m~38.21m, deposit of swamp facies; 38.21m~l1.62m, deposit of lacustrine facies; 11.62m~0m, deposit of lacustrine-swamp facies.Multiple environmental proxies of Xinghua core record the process and characters of palaeoclimate evolution of Northern Jiangsu Basin during the past 3Ma. During the period, the palaeoclimate of Xinghua has experienced several phases, 3.26~2.68Ma, relatively humid period; 2.68~2.32Ma, relatively arid period; 2.32-2.13Ma, relatively humid period; 2.13~1.50Ma, relatively arid period, during which there are some little humid fluctuation; 1.50~1.00Ma, relatively humid period; 1.00~0Ma, humid and arid period alternate frequently, during which at least 6~7 prominent fluctuation gyrations have been recorded.The research results also indicate that, the palaeoclimate of the typical monsoon area in Eastern China has experienced two prominent changes during the past 3 Ma. The period of 2.26-2.16Ma is the transition time of the formation of typical monsoon climate in China. Before this period, the palaeoclimate recorded by sediment had many characters that belong to Savanna. The palaeoclimate had not completely deviated from the Pliocene pattern in many aspects. The typical monsoon climate of high-temperature and high-humidity had not come up in Northern Jiangsu Basin until 2.16Ma. The other change happened in the period of 0.9~OMa, in this period, the difference between ice age and interglacial was obvious and there is prominent process of ice age and interglacial.The arid-humid fluctuations since around 3 Ma disclosed by Xinghua core reveals a strong correlation with the deep-sea oxygen isotope record and loess-plateau record. Particularly, as to the environmental change process since Brunhes, the results not only has great comparability with the wind sediment hi this area, but also has strong accordance with the Northern loess-plateau record and deep sea oxygen isotope record. This indicates that the climate change in Eastern China not only has great regional character, but also has great correlation with the global climate changes.The comparison of climate change in Eastern area since Late Pliocene indicates that, the formation of typical monsoon climate in Eastern area varies with the geographical location. To some extent, the difference shows that, in Early Quaternary, the monsoon that influenced Eastern area was not strong, and the area it affected was very limited. But as the monsoon strengthened and its influenced area enlarged, the monsoon climate finally has influence on the whole Eastern area until the end of Early Pleistocene.The research also indicates that, the climate change in Eastern China has great correlation with the uplift of Tibetan Plateau, the Kuroshio and t更多还原