应用音频大地电磁法探测内蒙古巴丹吉林高大沙山结构及成因

巴丹吉林沙漠拥有世界罕见的高大沙山群。为了解巴丹吉林高大沙山结构与成因,应用音频大地电磁法进行测量,利用非线性共轭梯度法二维反演得到了沙山的横截电性剖面。沙山电性剖面深部呈现明显的低阻,而沙山中部存在一定规模高阻区域。判断巴丹吉林沙漠众多高大沙山群的形成是由其稳定的西北风作用、源源不断的地下水补给机制和特殊的地层环境共同作用的结果。地下水由于蒸腾作用上升遇到古老沙丘的钙质层阻挡,由背风坡底部蒸发出来。水蒸气凝结在顶部滚落的沙子表面,使其抗风蚀能力增强,起到固沙作用;随着时间推移,沙山越来越大,形成高大沙山。

Applying Audio-magnetelluric Method to the Study of Megadune Structure and Formation in Badain Jaran Desert, Inner Mongolia

Badain Jaran Desert has a rare group of megadunes in the world;the audio-magnetelluric(AMT) method was used to study the structure of megadunes in Badain Jaran desert.The audio-magnetelluric data was processed by nonlinear conjugate gradients method,and the resistivity sections of megadunes were obtained.There is a apparent low-resistivity zone existing in the deep of the section,and a certain scale high-resistivity zone in the central of the megadunes.It is inferred that the formation of megadunes is relat...