常用地球物理方法勘探深度研究

Study on the exploration depth of geophysical methods commonly used

地球物理勘探在地学研究中起到十分重要的作用,其方法种类较多,在各类物探方法的具体工作中,了解相应方法所能探测到异常体的深度范围,对物探工作的开展十分重要.本文通过对当前地面重力与磁法、常用的电法、放射性方法以及常用的各类航空物探方法在找矿等方面的众多实例勘探深度的研究,总结归纳了现阶段各种常用地球物理方法的勘探深度.总结发现目前重力勘探的找矿深度一般在400 m左右,最大可达到897 m;在地质构造研究方面勘探深度在10~20 km之间,结合其他物探方法最深可达到150 km.目前磁法勘探找矿深度一般在400~500 m,最大深度可达到989 m.电法勘探分支方法较多,多数电法的勘探深度在200~300 m;瞬变电磁法的勘探深度集中在300~400 m,最大可以达到1500 m;大地电磁法的勘探深度集中在700~800 m,最大可达到1800 m以上.放射性勘探主要集中于地表至200 m以浅的放射性矿产勘探.并以典型实例说明各种物探方法可达到的最大深度,研究了影响各种地球物理方法勘探深度的因素,根据总结得到的各类地球物理方法勘探深度,对不同物探方法所适用的地质研究领域与深部找矿方向进行了展望,为实际工作的设计提供参考.

Geophysical exploration plays an important role in the geological studies. It has a variety of methods. Clearing the depth range of the abnormal body can be detected by different methods is very important to carry out geophysical prospecting work. In this paper,through the study of the current gravity and magnetic method, commonly used methods of electrical and radioactive methods,as well as many types of airborne geophysical prospecting methods in the exploration of the depth of exploration, the exploration depth of various geophysical methods are summarized,The exploration depth of gravity exploration is generally in the 400 m in geological prospecting,the maximum exploration depth is up to 897 m. The exploration depth of gravity exploration is in the 10 ~20 km in the study of geological structure. Combined with other geophysical methods,its depth can reach 150 km. The exploration depth of magnetic prospecting is generally in the 400 ~ 500 m in geological prospecting,the maximum exploration depth is up to989 m. There are many branches of electrical prospecting. The depth of most electrical prospecting methods is in the 200 ~ 300 m.The exploration depth of the transient electromagnetic method is concentrated in 300 ~ 400 m,and the maximum can reach 1500 m.The exploration depth of the magnetotelluric method is concentrated in 700 ~ 800 m,and the maximum can reach more than 1800 m.Radioactive exploration is mainly focused on explorating the radioactive mineral from the surface to 200 m. In this paper several typical examples are given to show the maximum depth of various geophysical methods,the factors that influence the exploration depth of various geophysical methods are summarized as well. According to the exploration depth of various geophysical methods summaried by the paper,the geological research fields and the deep prospecting direction of different geophysical methods are prospected. All the contents mentioned above could provide reference for geological prospecting work.