Abstract：Interpolation-cut method is usually used to separate local field from areal field of magnetic anomaly. The method can be also taken to ascertain distribution of igneous masses because most of igneous rocks have obvious magnetic characteristics.Mere it needs the following steps:With the use of a big cut radius，the local magnetic anomaly due to igneous mass is separated out from the real magnetic anomaly that has been reduced to the pole and underwent noise elimination processing.The local magnetic anomaly undergoes a series of interpolation-cut processings in different cut radius (starting from the minimum one) to produce a series of corresponding new local magnetic anomalies.The homologous cut radian is equivalent to the center depth of the igneous mass relating to the local magnetic anomaly when the magnetic anomaly goes the stable limit.The method is far globular igneous mass. Igneous masses in other shapes need an additional special processing.
