Tectonic Phase Separation Applied to the Sudetic Marginal Fault Zone(NE part of the Czech Republic)  

作　　者：NOVAKOVA Lucie 

机构地区：[1]Department of Seismotectonics,Institute of Rock Structure and Mechanics, Academy of Sciences,v.v.i.,V Holesovickach 41,Prague 8,Czech Republic

出　　处：《Journal of Mountain Science》2015年第2期251-267,共17页山地科学学报（英文）

基　　金：supported by the Grant Agency of Charles University (43-258020);the Czech Science Foundation (250/09/1244);the Institute of Rock Structure and Mechanics AS CR, v.v.i. (A VOZ30460519)

摘　　要：This study emphasizes the advantage of tectonic phase separation in determination of a tectonic evolution of complicated fault zones. The research focused on the Sudetic Marginal Fault Zone(SMFZ) –a 250 km long active fault zone with documented intraplate seismicity situated on the NE margin of the Bohemian Massif(the Czech Republic). The tectonic history of the SMFZ as well as its kinematic development has been rather complicated and not quite understood. A field structural investigation was carried out in extensive surroundings of the fault zone. The fault-slip data were collected in a number of natural outcrops and quarries with the aim at establishing a robust and field-constrained model for local brittle structural evolution of the studied area. A paleostress analysis was calculated using the collected fault-slip data inversion. The T-Tecto software was utilized for semiautomatic separation of the paleostress phases. Simultaneously three methods of data separation were employed:(1) the Gauss inverse method,(2) the Visualization of Gauss object Function, and(3) the frequency analysis. Within the fault zone multiphase movements were observed on various types of faults as well as wide range of the kinematic indicators orientations. The frequency analysis confirmed the multiphase history of the SMFZ. The calculated tectonic phases were divided according to their relative age as constrained by cross cutting relationships and, where observed, multiple striations on a single fault plane and classified from the oldest to the younger. Data separation and inversion usingT-Tecto software with the Gauss inverse method revealed four different stress phases which are 3 strike-slip stress regimes and one compressional regime. The strike-slip regimes are characterized by σ1 trending NW-SE(43), NNE-SSW(18), ENE-WSW(76) and the compressional one by σ1 trending W-E(26). First, compression occurred parallel to the SMFZ supposedly during the Variscan period. Second, compression at an angle of 60° to general direction of the

关 键 词：Sudetic Marginal Fault Zone Paleostress reconstruction Active tectonics Frequency analysis 

分 类 号：P315.2[天文地球—地震学] P618.130.2[天文地球—固体地球物理学]