【作者】 李慧；

【导师】 李才明；

【作者基本信息】 成都理工大学 ， 应用地球物理， 2010， 硕士

【摘要】 磁法勘探中研究的磁异常场,大都属于地壳中局部的磁异常,即磁性地质体的磁场。这种磁性地质体的磁场在地表上空间分布的形态特征,直接受局部磁性地质体形状、大小、产状和磁化强度等因素的控制。因此,为了了解地下岩层、岩体分布特征、构造特征和矿产分布的特征,我们是根据测得的磁异常分布特征进行分析,做出判断的。由于多数教科书及参考文献上对航空磁测△T的平面及空间特征分析较少,使得在对航空磁测以及现在地面磁测资料解释推断时缺乏参考,本文通过自主编程计算出各种规则磁性体的△T异常,从理论上讨论了各种规则磁性体△T异常的剖面、平面、断面特征。本文首先讨论了各种规则磁性体的△T异常,得出单个磁性体△T异常的平面等值线形状大体可分为三种,即长带状、等轴状和椭圆状;主剖面曲线有三种基本形态:两侧无负异常的△T曲线、一侧有负异常的△T曲线和两侧都有负异常的△T曲线。然后,对△T、Z a异常进行了比较,得出△T与Z a异常在平面、剖面、断面上的曲线形态都是类似的,不同之处:在主剖面上,有△T极小值的绝对值大于Z a极小值的绝对值;△T平面等值线的零值线是一条曲线,将异常分为正负两部分,而Z a的零值线是圈闭的,包围着正异常,△T的负值范围小于Z a。最后,将所研究的结果应用到尼雄地区的反演计算中,得出了与钻探剖面相符的结果。理论模型的计算及实际资料的应用结果表明,本文所做的研究,对以后航空磁测及地面磁测资料的解释推断具有一定的指导意义。更多还原

【Abstract】 The magnetic anomaly field studied in magnetic prospecting, mostly pertain to the local magnetic anomalies in the crust, namely the magnetic field of magnetic geologic body. The morphological character of space distribution on shallow ground of these magnetic geologic body are controlled directly by factors of shape, size, formation state, magnetic intensity of local magnetic geologic body and so on. Therefore, in order to understand the character of the underground terrane and rockmass of distribution, conformation and mineral distributing ,we can analyse and estimate the character of the magnetic anomaly we surveyed.Since the majority of textbooks and reference literatures about the analysis of△T character in plane and space of aeromagnetic survey are less, the aeromagnetic and ground magnetic data is lack of reference in interpretation and inference. In this paper, we through self-programing to calculate the△T anomaly of variety rules magnetic body , theoretically discussed the profiles, plane, the cross section features of△T anomaly of variety rules magnetic body.In this paper, firstly, we discussed△T anomaly of various rules magnetic body , and concluded that the contour shape of a single magnetic△T anomalies can be roughly divided into three types: long strip, equiaxed and elliptical; Main profile curve has three basic forms: both sides of the△T curve with no negative anomalies , one side of the△T curve with negative abnormal, and negative anomaly on both sides of the△T curve.In addition, comparing△T and Z a anomaly, we obtained that the curve shape of△T and Z a anomaly in the plane, profile, cross section is similar, the difference between them is in the main profile the absolute value of a minimum value of△T anomaly is greater than that of Z a anomaly .And the zero value contour line of △T anomaly is a curve, dividing the anomaly into two parts of positive and negative, while the one of Z a anomaly is closed, surround the positive anomalies, the negative range of△T anomaly is less than Z a anomaly .Lastly, the results of the study were applied to the inversion calculation of NiXiong region , and the results are consistent with the drilling profiles.Theoretical models together with actual data applications show that the research has been done in this paper with some guidance for the interpretation and inference of the aeromagnetic and ground magnetic survey data .更多还原