中国黄土^(10)Be重建古地磁场变化史的初步研究

Preliminary study on the reconstruction of the paleogeomagnetic intensities by ^(10)Be in Chinese loess

针对黄土磁性记录重建古地磁场变迁及黄土^(10)Be示踪古地磁场变化史的问题,提出了将黄土磁化率作为黄土^(10)Be浓度受气候因素(降水和降尘)影响部分的代用指标,以及分离黄土^(10)Be浓度中受地磁场调制和受气候影响的不同组分的思路。在平均值概念(MVC)基础上,引入了气候修正因子,进一步消除了气候因素对^(10)Be浓度变化的影响;从西峰和洛川黄土剖面的^(10)Be记录重建了过去80 ka、130 ka及700~900 ka大气^(10)Be产率史,有助于解决中国黄土^(10)Be环境示踪和重建全球古地磁场变化史的科学难题。

In this paper, the difficulties were summarized in the reconstruction of the paleogeomagnetic intensities by using either the paleomagnetie approach or the ^10Be records in Chinese loess; a new idea was put forward that takes the susceptibility as a climate proxy of ^10Be composition affected by climate factors （ Monsoon precipitation and dust flux） to separate the influence of the climate factors from that of the geomagnetic factor on the measured concentration in loess samples. A climate correction factor was introduced into the MVC method based on the mean value concept（MVC） to further clear up the effect of the climate change on the reconstructed results; the past 80 ka, 130 ka and 700 -900 ka ^10Be production rates in atmosphere have been reconstructed, in turn, the global paleogeomagnetie intensities, which have facilitated to solve the academic difficult in environment trace research from ^10Be records in Chinese loess.