タイ・マレーシアにおける物理探鉱

Abstract

This paper is the result of a preliminary survey in Thailand and Malaysia of geophysical prospecting made during November and December, 1964. Geophysical prospecting is the method used to search for deposits of minerals by physical measurments of the earth's surface. These measurments give information as to the physical properties of materials within the earth. Such information can be used to locate mineral deposits. There are five major methods used in geophysical prospecting : the seismic, gravitational, electrical, magnetic, and radioactive methods. Geophysical prospecting is a comparatively young science, and in Thailand and Malaysia it has not been much applied. The ore deposits which were investigated in this preliminary survey were iron, cassiterite, manganese, and fluorite. In prospecting for iron ore deposits, the magnetic and electrical methods can be used. The magnetic method is used in airborne as well as ground prospecting operations while the electrical method is used only in ground prospecting operations. To prospect for cassiterite and manganese deposits, the electrical method can be utilized in ground prospecting operations. It is rather difficult to prospect for fluorite deposits by geophysical methods, because the physical differences between fluorite deposits and ordinary indigenous rocks are hardly distinguishable. Since ore deposits widely distributed in the Southeast Asian area are of great concern to Japan, a cheap geophysical prospecting method which can be easily understood and utilized by Southeast Asian engineers is highly to be desired. It was determined that the geophysical prospecting which will be undertaken in 1965 in northern and southern Malaysia was to be for iron ore deposits and that the method used would be the magnetic method in ground prospecting operations with the electrical method to be used as well where necessary.