中文摘要：

Theta图是利用位场（重磁）数据识别边界的常用方法,其表达式为重磁异常水平变化与垂直变化的比值函数.该方法计算浅源地质体边界的效果较好,而由于深源位场数据在换算过程中会产生趋同效应,在深源地质体识别应用中计算结果不准确,为此,本文提出Theta-Depth法并进行地质体埋深的计算.首先给出直接利用Theta图像进行场源体深度估算的方法,然后推导出基于Theta导数的线性方程来自动估算场源位置参数,本文方法可有效地利用Theta图像的特征为约束条件来提高反演结果的精度.理论模型试验证明本文提出的Theta-Depth法能有效地计算出场源体位置和深度.将该方法应用于满都拉地区实测磁数据的解释,帮助圈定了矿脉的分布.

英文摘要：

The Theta map is a commonly used tool to detect edges of subsurface geological bodies using potential field（gravity and magnetic）data,which is the ratio of function of horizontal derivative to vertical derivative of gravity or magnetic anomalies. Although the effect of calculation of shallow geological body edges by this method is good,it is not successful in probing the deep geological body edges process due to the convergence of the conversion process that leads inaccurate calculation.To solve this problem,we proposed the Theta-Depth method to compute the depth of the buried geological body.Frist,we directly used the Theta map to estimate the depth of the source.Then we derived a linear equation based on the derivatives of Theta to compute the location and depth of the source.The presented method can use the Theta map as a constraint to obtain more accurate results effectively.The tests show that this Theta-Depth method can effectively calculate the location and depth of the source.We applied the Theta-Depth method to interpretation of measured magnetic data in the Mandula area,which helped delineate the distribution of ore veins.