衡阳盆地红土剖面磁化率分布特征及其指示意义

Magnetic Susceptibility Distribution Characteristics of Laterite Profile in Hengyang Basin and Its Indicative Significance

通过采集衡阳盆地高兴(GX)和松木(Hz)2个红土剖面不同深度土样,测试磁化率及化学风化系数,对衡阳盆地高兴与松木红土剖面低频质量磁化率与硅铝系数、铝铁系数、铝铁硅系数及氧化铁含量进行分析。结果表明:红土剖面不同深度处磁化率不同;从整体来看,高兴剖面红土平均低频质量磁化率值从上至下呈递增到递减又递增的趋势,松木剖面平均低频质量磁化率值从上至下呈先递减后递增再递减的趋势;高兴剖面红土磁化率与硅铝系数成正相关,相关性强,r=0.678 3。与铝铁、铝铁硅、氧化铁成负相关关系,相关系数较小;松木剖面红土磁化率与硅铝、铝铁系数成正相关关系,与铝铁硅、氧化铁成负相关关系,属中等程度相关性。

The magnetic susceptibility and chemical weathering coefficient of the two clay samples of Gaoxin(GX)and Songmu(Hz)in Hengyang basin were collected,and the low-frequency mass magnetization rate,Si-Al coefficient,Si-Fe coefficient,Al-Fe-Si coefficient and ferric oxide content of the laterite profile in Hengyang basin were analyzed.The results show that the magnetic susceptibility is different at different depths of laterite profile.On the whole,the average low-frequency mass susceptibility of laterite in Gaoxin section increases from top to bottom and then decreases.The average low-frequency mass susceptibility of Songmu section decreases first,then increases and then decreases from top to bottom.The magnetic susceptibility of laterite in Gaoxin Section is positively correlated with the coefficient of Si-Al,and the correlation is strong,r=0.678 3.It has a negative correlation with Al-Fe,Al-Fe-Si and Fe-O,and the correlation coefficient is small.The magnetic susceptibility of laterite in Songmu profile is positively correlated with the coefficients of Si-Al and Si-Fe,and negatively correlated with the coefficients of Al-Fe-Si and ferric oxide,which is moderately correlated.