General Geophysical Study and Others
Geophysical methods are now used extensively and effectively in China in the search for base, rare, and noble metal ore deposits. They are used not only to detect orebodies directly but also to study the geologic structures encountered in the process of exploration.
Geophysical methods are very effective in studying geologic structures and factors related to tin ore deposits. With the help of aeromagnetic surveys (scale 1:200 000) and ground gravity surveys (scale 1:200 000), a buried granite intrusive mass was detected in the Gejiu (Laojunshan) area and thus a favorable place for prospecting was delineated. A new tin ore deposit was then discovered by detailed ground geophysical and geochemical work.
Based on an anomaly classification scheme following regional surveys (scale 1:200 000), geophysicists selected interesting anomalies for detailed surveys in the north-eastern part of Jiangxi Province. New discoveries were made.
The three main factors which contribute to the successful use of geophysics in locating nonferrous ore deposits are (1) mapping geologic structure, (2) classifying anomalies by using special indicators such as amplitude and pattern, and (3) establishing geophysical-geological models.