THE INVESTIGATION OF THE UNITY BETWEEN THE NORTHERN PART OF THE NS-TRENDING TECTONIC ZONE AND THE SEISMIC ZONE FROM THE CHARACTERSITICS OF THE GRAVIMETRIC AND MAGNETIC FIELD
LI Xu-shan1, LI Bai-xiang2
1. Gansu Institute of Geological Survey, Lanzhou 730000, China; 2. No. 2 Geological and Mineral Exploration Party, Gansu Bureau of Geology and Mineral Resources Exploration and Development, Lanzhou 730020, China
Abstract:Starting with an analysis of the characteristics of the geophysical field, this paper puts forward the evidence for determining the NS-trending tectonic zone on the basis of the east and west differences of NS-striking gravity gradient zone and gravity-magnetic field characteristics, and investigated the regional and deep geological-structural background for the formation of NS-trending tectonic zone as well as the corresponding relationship of the zoned distributions of the earthquakes. The NS-trending tectonic zone reflected by the gravitational gradient zone has not only inheritance manifested by its consistency with the central axis structure but also newborn nature of westward expansion. In addition, there exists the superimposition of the segmentation on the basis of the unified NS-trending zone. It forms the earthquake-controlling and heat-controlling mechanism in different backgrounds of southward compression and northward expansion. It also constitutes the east-west dividing line between the eastern boundary of the Tibetan Plateau and China's continental tectonic domain, corresponding to the narrow sense NS-striking seismic zone.
李绪善, 李百祥. 从重磁场特征探讨南北构造带北段与地震带的统一性[J]. 物探与化探, 2012, 36(5): 760-765,771.
LI Xu-shan, LI Bai-xiang. THE INVESTIGATION OF THE UNITY BETWEEN THE NORTHERN PART OF THE NS-TRENDING TECTONIC ZONE AND THE SEISMIC ZONE FROM THE CHARACTERSITICS OF THE GRAVIMETRIC AND MAGNETIC FIELD. Geophysical and Geochemical Exploration, 2012, 36(5): 760-765,771.