Osborne Kubeka Zenzele
China University of Geosciences (Beijing), School of Geophysics and Information Technology, No.29, Xueyaun Road, Haidan District, Beijing, China.
Heliyon. 2024 Aug 23;10(17):e35934. doi: 10.1016/j.heliyon.2024.e35934. eCollection 2024 Sep 15.
The general tectonic structural architecture of southern Africa is an ensemble comprised of Kalahari Craton, a vast range of mosaics of the best-preserved geological Belts, and exposed crustal blocks. In the region, demarcation of geological boundaries, tracing of magnetic and gravitational bodies, and detrending lineaments are essential to understanding the structural limits. The study presents the prevalent gravitational and magnetic investigation of major geological Belts, enhancing edges of Cratons, and evaluation of surface invariants to improve the geological understanding and evaluate the correlation of structures with the general structural tectonic framework. The utilized filter methods in the gravity maps are the Directional derivatives along x, y, and z-directions, the Modulus tensor, the Total horizontal derivative, and the Tilt angle techniques. The phase-based filters used in the magnetic section include the Total horizontal derivative, Analytical signal, Tilt angle method, Tilt of total horizontal derivative, Theta method, Horizontal tilt angle method, Enhanced tilt filter, and Enhanced total derivative of the tilt angle. The Directional derivatives of the gravity field and the Modulus of the gravity gradient tensor demarcate the boundaries of geological structures. The Total horizontal derivative method gives an immediate and easy-to-read image of the linear structures and fault systems. The signal cluster on the Analytical signal and Tilt angle maps delineate the boundaries of causative geological sources. The Theta map is comparable with the enhanced total derivative of the tilt angle. The Tilt of the total horizontal derivative, Theta map, and Enhanced tilt filter accentuate the traces of magnetic bodies, including the Cratons. The study finds regional lineaments surrounding the Cratons and concentrated along the geological Belts. The approach of using joint elegant filters is effective and increases the certainty of the interpretation.
南部非洲的总体构造结构体系是由卡拉哈里克拉通、一系列保存最完好的地质带镶嵌体以及暴露的地壳块体组成。在该地区，划定地质边界、追踪磁性和重力体以及去除趋势线理对于理解构造界限至关重要。本研究展示了对主要地质带、克拉通边缘的重力和磁性调查，以及对地表不变量的评估，以增进地质理解并评估结构与总体构造框架的相关性。重力图中使用的滤波方法包括沿x、y和z方向的方向导数、模量张量、总水平导数和倾斜角技术。磁测剖面中使用的基于相位的滤波器包括总水平导数、解析信号、倾斜角法、总水平导数的倾斜、θ法、水平倾斜角法、增强倾斜滤波器和倾斜角的增强总导数。重力场的方向导数和重力梯度张量的模量划定了地质结构的边界。总水平导数法能立即给出线性结构和断层系统的清晰易读图像。解析信号图和倾斜角图上的信号簇描绘了地质源体的边界。θ图与倾斜角的增强总导数相当。总水平导数的倾斜、θ图和增强倾斜滤波器突出了包括克拉通在内的磁性体的踪迹。研究发现了围绕克拉通并沿地质带集中的区域线理。使用联合精细滤波器的方法是有效的，提高了解释的确定性。
