论文部分内容阅读
建立了10Be产率-古地磁场强度的便捷转换方程,并以洛川剖面最近80ka的10Be浓度记录结合磁化率等气候代用指标为研究对象,利用全新的LGM分离方法将影响黄土10Be浓度的气候因素和地磁场因素进行了分离,成功示踪了末次冰期阶段拉尚(Laschamp(42ka))、莫诺湖(Mono Lake(32ka))等古地磁漂移事件,进而定量重建了最近80ka地磁场强度变化历史.重建结果与全球典型地磁场强度曲线(SINT-200,NAPIS75等)具有几乎同步的变化特征,从而表明采用LGM方法和新的转换方程在利用黄土10Be记录示踪和重建古地磁场强度研究中的实用意义及应用前景.通过分析表明,季风区降水的不均匀性是导致黄土10Be浓度无法直接示踪古地磁场漂移事件的主要原因,而来自粉尘源区的尘降10Be浓度和尘降磁化率具有“准恒定分布”特征.
A convenient conversion equation of 10Be yield and paleomagnetism field intensity was established and the climatic proxies such as the magnetic susceptibility combined with the 10Be concentrations of the recent 80 ka in the Luochuan section were recorded. The new LGM separation method was used to influence the climate of 10Be concentration in loess And the geomagnetic field factors, the paleomagnetic drift events such as Laschamp (42 ka) and Mono Lake (32 ka) in the last glacial stage were traced successfully, and the magnetic field intensity of the last 80 ka The result of the reconstruction shows almost synchronous characteristics with the typical global magnetic field strength curve (SINT-200, NAPIS75, etc.), which shows that the LGM method and the new transformation equation are used to track and reconstruct the paleomagnetic strength The practical significance and application prospects of the study are as follows: The analysis shows that the nonuniformity of precipitation in the monsoon region is the main reason that the loess 10Be concentration can not directly trace the paleomagnetic field drift events, and the dust concentration and dust from the dust source region Demagnetization rate has a “quasi-constant distribution” feature.