Study on igneous rocks identification using full gradient of potential field based on discrete cosine transform

Edge detection and enhancement techniques are usually used in identifying the boundary of geologic bodies using potential field data. In this paper, we present an igneous rocks identification method using full gradient of potential field based on discrete cosine transform. Rocks physical properties for igneous rocks usually have high-density and high magnetic susceptibility, with strong gravity or magnetic anomaly. So it's available to identify the boundaries and distribution of igneous rocks using full gradient of gravity and magnetic anomalies method. Discrete cosine transform was used in computing full gradient of potential field to improve the computational speed and accuracy. The modeling test proves good results based on the method we have discussed. Using this method, we identified igneous rocks distribution of northwestern South China Sea and its adjacent regions.