Abstract：Small subdomain filtering(SSF) is widely used for picking anomaly boundaries of gravity data,but the method could make anomaly curve distorted because of the unreasonable subdomain division.In this paper,the subdomain division pattern of SSF was improved to reflect the structures with diffe-rent strikes.Moreover,a stable anomaly-enhanced filtering method based on iterative differential was proposed to solve the problem that small subdomain filtering is easily affected by high-frequency disturbance and enhance anomaly boundary identification.Compared with the conventional SSF,in model tests,the improved SSF of enhanced anomaly is more stable,and the detected edges are more consistent with boundaries of field sources.In the application to the gravity data of Yalu River Basin,the improved SSF of enhanced anomaly output more detailed results than conventional SSF.The detected boundaries match lithologic contact zones well,and the negative value area can generally reflect the distribution of low-density rocks in research area.It demonstrated the effectiveness and practicability of the method proposed in this paper,and the results facilitate coalfield exploration and geological-geophysical comprehensive interpretation.
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