为了解广西花山-姑婆山花岗岩体的三维形态,使用广西花山-姑婆山花岗岩体的重力资料,首先在花岗岩体的露头范围内,选择一些均匀分布的重力剖面,采用人-机联作的2.5维重力模拟反演方法,求出岩体的断面形态;综合这些断面图,描述花岗岩体的三维切片形态。其次,用粒子群法进行重力三维反演,利用岩体的出露部分和对重力异常上延不同高度求垂向三阶导数的零值线作为参考约束条件,直接反演出岩体的三维分布,绘制花岗岩体的三维立体图。结果表明,花山-姑婆山花岗岩体最大分布面积约为1 596 km2,花山岩体的最大厚度约为11.6 km,姑婆山岩体的最大厚度约为22.7 km。
Inference of the three-dimensional geometry in Huashan-Guposhan granite mass at depth from 2.5 dimensional(2.5D) gravity forward modeling,by particle swarm inversion method,and by gravity data in Guangxi is presented.Within the limit of granite outcrops,a number of uniformly distributed gravity profiles are selected.The geometry of the granite on a cross-section is illustrated by 2.5D gravity forward modeling.A synthetic diagram consisting of all the successive profiles shows a 3D geometry of the Huahan-Guposhan granite mass.3D geometry of the granite is inversed by particle swarm inversion method,and a three-dimensional granite map drawn.In the particle swarm inversion process,the zero line found by the part of exposed rock and upward continuation at different height and vertical third derivative of gravity anomalies is a reference constraint.The results show that the whole area of the Huashan-Guposhan granite mass is 1 596 km2,the maximum thickness of Huashan rock mass is about 11.6 km,and the maximum thickness of Guposhan rock mass is about 22.7 km.