1�� College of Geo- Exploration Science and Technology��Jilin University��Changchun 130026��China; 2�� College of Engineering and Natural Sciences��University of Tulsa��Tulsa OK 74137��USA

The identification of fractures is of great importance in gravity and magnetic data processing and in- terpretation�� In this study��four fracture identification methods are applied��and widely used in processing and analysis of the gravity anomaly��including vertical second derivative method��tilt derivative method��theta map method and normalized differential method�� for gravity data acquired in a given area in Heilongjiang�� By compa- ring the distribution of the zero contour or maximum contour��we summarize the application effects��and both advantages and disadvantages of each method�� It is found that tilt derivative method and normalized differential method provide better effects than other two methods: the narrower anomaly gradient belt and higher identifica- tion precision of fracture or geological boundary�� The inferred fractures and geological boundaries have a great match with the results obtained from geologic map and remote sensing data interpretation�� Those study results have definitely provided the theoretical foundation for identifying faults and the geological boundaries��