tailieunhanh - Using the analytic signal method of gravity gradient tensor (GGT) to determine the location and depth of the faults in the Pre-Cenozoic basement rocks of the Red River trough

In this paper, we present the study results of using the directional analytic signal method of gravity gradient tensor (GGT) and the Euler deconvolution of the directional analytic signals to determine location and estimate the depth of fault systems in the Pre-Cenozoic basement in order to improve the efficiency of Pre-Cenozoic basement structure. | Vietnam Journal of Earth Sciences Vol 38 (2) 143-152 Vietnam Academy of Science and Technology Vietnam Journal of Earth Sciences (VAST) Using the analytic signal method of gravity gradient tensor (GGT) to determine the location and depth of the faults in the Pre-Cenozoic basement rocks of the Red River trough Nguyen Kim Dung*1, Do Duc Thanh2 1 Institute of Marine Geology and Geophysics, Vietnam Academy of Science and Technology Hanoi University of Science, Vietnam National University 2 Received 12 August 2015. Accepted 13 April 2016 ABSTRACT In this paper, we present the study results of using the directional analytic signal method of gravity gradient tensor (GGT) and the Euler deconvolution of the directional analytic signals to determine location and estimate the depth of fault systems in the Pre-Cenozoic basement in order to improve the efficiency of Pre-Cenozoic basement structure. The method is tested on the 3D digital model, which shows that not only the location and depth of resources are determined but also can overcome undue interference, which could be met in the previous analytic signal methods. To study more about the applicability of the method, we applied the method for the gravity anomaly data of Red River Trough. Obtained preliminary results have shown the location of major faults in the region: Song Lo fault, Song Chay fault, Red River fault, etc. and initially (in the first time), by this method, the depth of over 10 km the fault persists. This depth is deeper than the depth of the surface of Cenozoic boundary determined by other methods, proves that the faults appear in the Pre-Cenozoic basement. Keywords: Gravity gradient tensor; Euler deconvolution; fault; analytic signal. ©2016 Vietnam Academy of Science and Technology 1. Introduction Researches on the Pre-Cenozoic basement structure, especially location and depth of the fault in the basement rock determined by gravity anomalies data always get the .