Gravity and magnetic anomalies field characteristics in the South China Sea and its application for interpretation of igneous rocks

Igneous rocks in the South China Sea have broad prospects for oil and gas exploration. Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify igneous rock bodies. Aimed at the characteristics of gravity and magnetic fields in the South China Sea, several potential field processing methods are preferentially selected. Reduction to the pole by variable inclinations in the area of low magnetic latitudes is used to perform reduction processing on magnetic anomalies. The preferential continuation method is used to separate gravity and magnetic anomalies and extract the gravity and magnetic anomaly information of igneous rocks in the shallow part of the South China Sea. The 3D spatial equivalent distribution of igneous rocks in South China Sea is illustrated by the 3 D correlation imaging of magnetic anomalies. Since the local anomaly boundaries are highlighted gravity and magnetic gradients, the distribution characters of different igneous rocks are roughly outlined by gravity and magnetic correlation analysis weighted by gradient. The results show the distribution of igneous rocks is controlled and influenced by deep crustal structure and faulting.