Gravity and Magnetic Anomalies of Overlapping and Closely Spaced Multiple Bodies

Near-Surface Geophysics is to understand the subsurface geological settings and the success of these methods is based on certain assumptions and constraints. The gravity and magnetic methods are highly useful and most popular geophysical techniques in mineral exploration and structural delineations. In reality the endogenic and exogenic geological processes produce most irregular shaped bodies and many times multiple in nature occurring side by side and overlapping with one another. Gravity and magnetic anomalies on such closely spaced bodies cannot produce distinguished anomalous features. This paper deals with the gravity and magnetic anomaly characteristics over closely spaced multiple bodies and their possible misinterpretations. For this a number theoretical closely spaced models considered by varying the model parameters such as depths and dips. The inversion of these model anomalies yields the possible misinterpretations and criteria to distinguish the multiple bodies. The interpreted abnormally high density in gravity inversion and fluctuations on a broad magnetic anomaly profile may indicate the presence of closely spaced multiple subsurface bodies. Many times overlapping subsurface geological formations produce cumulative gravity and magnetic anomaly responses with small undulations over a broad anomaly trends which needs to be decomposed based on the anomaly trends and local geology.