【摘要】 对取自洪湖的 140cm沉积物样芯进行了环境磁学测量,分析了所获得的环境磁学参数随深度变化的曲线,结果表明,沉积物磁性特征由稳定单畴(SSD)和细粘滞性 (FV)亚铁磁性矿物所主导,磁性矿物颗粒由下至上粒径逐渐减小。结合AMS测年和地球化学分析,可以推断出洪湖在 1200a来经历了沼泽沉积和湖相沉积。并且磁性特征的变化与气候的变化大致对应:磁性参数较大值对应着冷干的气候条件;水热条件增强时,磁性参数值下降。较好记录了湖泊随气候的扩张和缩小过程,同时也反映了人类活动的影响。更多还原

【Abstract】 Based on the environmental magnetic measurement on the core with the length of 140cm collected from Honghu Lake, it has been analyzed the chart that the environmental magnetic parameters vary alone with the depth. The result suggests that the stable single domain and fine viscous ferromagnetic minerals dominate the characteristics of sediments. The magnetic minerals grain size increasingly reduces from the bottom to top. By combination AMS dating and geochemistry analyses, it can be deduced that Honghu Lake experiences swampy and lacustrine sediment from last 1200a. Moreover magnetic characteristics changing corresponds to palaeoclimatic changes. In cold and dry condition, the magnetic parameters are higher than that in warm and wet condition. They record the course that Honghu Lake extends and shrinks along with climate; at one time reflects the human activities’ impact on the lake.更多还原