应用优化程序分析宁芜火山基底构造特征

Application of optimization program in the analysis of tectonic characters of volcanic basement in Nanjing—Wuhu area

根据共轭剪切节理求解出三个主应力轴的空间方位,再用极射赤平投影办法绘制主应力图解来分析古构造应力场是目前区域构造研究的有效方法之一。但该法的实施涉及大量数据,手工换算和作图不仅繁琐。

The illustration of principal stress usually used in the calculation of stress has a comprehensive program and unperfect output mode.The author improves primary program to set up a new optimization program.The correlation between old and new programs confirms that the accuracy of new program is higher than that of old program.Practically,the author has recalculated measuring data of joints in the volcanic basement in Nanjing—Wuhu area and draughted a new map of tectonic stress field.The author deems that the deformation of volcanic basement in this area belong to a plane stress field which the northern and central sections form a broad syncline,the southern section develops many anticlines in tension,the direction of party principal stress is opposite from that of regional stress field.By using opti- mization program in joint statistics,favourable area for the mineralization can be easily blocked out.At present,a perfect region for prospecting is thought to locate in the intrusive belt in southern and northern parts of Nanjing—Wuhu area.