用于地壳弧形构造信息提取的四阶谱矩分析

基于谱矩的位场几何特征分析是一种新的自动边界识别方法，相较于传统方法能够更均衡、收敛地识别地质体的几何特征。二阶谱矩可用于提取线形刻痕，但不能很好地识别其他刻痕。应用四阶谱矩可以进一步完善对弧形等刻痕信息的识别，为此提出弧形刻痕系数。理论试验表明，该系数可反映圆弧形或者交会线形刻痕的几何特征，且对深度的敏感性较低，故可用于提取位场中弧形刻痕的弱信号。该方法应用于塔里木盆地磁异常数据，成功地识别出古火山群和其他等轴形状的地质体，说明应用四阶谱矩分析和信息提取技术可以揭示特殊的地壳组构。

Fourth-order spectral moment analysis for extracting the information of crustal arc structures

The geometric feature analysis of potential field based on spectral moment is a new and automatic edge detection method. It can identify more even and convergent geometric features of geological bodies than conventional methods. Second-order spectral moment can describe linear scratches,but it cannot well recognize other kinds of scratches. Fourth-order spectral moment can recognize arc and other scratches,so we propose an arc coefficient. Theoretical experiments show that the coefficient can reflect the geometric features of circular arc or intersecting linear scratches,and has low sensitivity to depth,so it can extract weak signals of curvature arc scratches in the potential field. Applied in the Tarim Basin,this method has successfully recognized isometric structures like paleo-volcanic group and other geological bodies based on magnetic anomalies,indicating that fourth-order spectral moment can extract necessary information and effectively recognize special crustal structures.