Abstract:
Late Paleozoic mafic dyke swarms are widely developed in Beishan and it’s adjacent areas, which reflect the regional tectonic stress field of the pre-existing fissures (joints) and the tectonic activities experienced after the formation of dyke swarms, and are of great significance for exploring magmatic activities, inverting the tectonic evolution process, and analyzing the coupling relationship between the geometric characteristics of the dyke and the tectonic stress. Combining remote sensing and geological methods, this paper interprets and extracts 1777 basic dykes from remote sensing images, calculates the trend data of dykes through geometric tools, summarizes the spatial distribution of dyke swarms, and discusses the genetic mechanism of dyke swarm in the study area corresponding to the continental dynamic evolution background when they were formed. The dominant strike directions of the dyke in the Beishan and its adjacent areas are concentrated in 0° ~ 65° and 320° ~ 360°. Most of the dyke are formed under the control of the tensile regional stress field during the regional extension and have tensile or shear properties, while some of the dykes are affected by the late collision and extrusion environment and have the properties of tensile shear. The dominant genetic mechanism of dyke swarms is regional extensional tectonics, and also the remote effect and hot spot effect of mantle plume.