本申请书拟以沉积分辨率高、磁信号强的广东湛江湖光岩玛珥湖为研究对象，通过对该湖末次盛冰期以来沉积物的岩石磁学性质、区域地磁场长期变化记录（包括方向和强度）及磁性气候记录进行综合分析研究，配合年轻地质年代学研究并结合前人的古环境代用指标分析结果，并将宇宙成因核素10Be这一工具尝试运用到玛珥湖的研究中来，旨在：1）客观分析具有精确年代框架下的我国低纬度热带地区玛珥湖沉积相对地磁场古强度记录的可靠性，并尝试建立短时间尺度上的区域地磁场长期变化曲线；2）探讨热带-亚热带地区该湖末次盛冰期-全新世的岩石磁学记录及其磁性气候学指示意义，为深入理解东亚季风区短时间尺度上的气候变化过程和机制提供新的证据；3）突出区域上和全球范围内关键季风区末次盛冰期以来典型地质记录的地磁、古气候古环境的对比，从短时间尺度上的地磁场、太阳辐射和古气候间可能存在的某种联系入手，探讨地磁场活动特征和气候变迁之间的相关性。

The Huguang Maar Lake (HML) retains plentiful paleoclimatic and paleoenvironmental signals. However, the interpretations of the East Asian summer and winter monsoon history as interpreted from present paleoenvironmental proxies at HML are less satisfactory. Because of its high sedimentation rate and strong magnetic signals, the HML sediments are also excellent targets for environmental magnetism, paleosecular variation and geomagnetic relative paleointensity study at ultra short timescale. By detailed paleomagnetic, mineral magnetic and magnetoclimatologic study for the HML since the Last Glacial Maximum, combined with AMS 14C dating and 10Be flux analysis, the purpose of this proposal is to assess paleomagnetic directional and relative paleointensity (RPI) recording fidelity of the HML sediments and attempt to retrieve high-resolution paleosecular variation record spanning the past 20 ka. Comparisons of the RPI records and 10Be flux variations from the HML with other typical terrestrial RPI and archeomagnetic records from East Asia are critical to evaluate the HML RPI recording reliability. By comparison with previous results from pollen, organic geochemistry, element content etc, we also discern paleoenvironmental significance of rock magnetic parameters encoded in the HML sediments, aiming at better understanding of the East Asian monsoon evolution history in subtropical China. The thorough comparison between high-resolution RPI and paleoclimatic signals recorded by the HML are also helpful for further probe of possible linkage among the Earth's magnetic field, solar irradiance and climate.