The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Han...The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Hangwula structural zone, which was a passive continental margin in the Early Palaeozoic and was transformed into an active continental margin in the Late Palaeozoic;3. the Shalazha structural zone characteristic of a mature island arc; 4. the Nuru-Langshan structural zone, which was a Proterozoic orogenic belt and later evolved into an extensional transtional crust in the Palaeozoic. The above-mentioned tectonic units differ remarkably in sedimentary formations, magmatic rock associations, metamorphism and geochemistry and are bounded by faults between one another.展开更多
Accurately characterizing the threedimensional geometric contacts between the crust of the Chinese mainland and adjacent regions is important for understanding the dynamics of this part of Asia from the viewpoint of g...Accurately characterizing the threedimensional geometric contacts between the crust of the Chinese mainland and adjacent regions is important for understanding the dynamics of this part of Asia from the viewpoint of global plate systems. In this pa per, a method is introduced to investigate the geometric contacts between the Eurasian and Indian plates at the Burma arc sub duction zone using earthquake source parameters based on the Slabl.0 model of Hayes et al. （2009, 2010）. The distribution of earthquake focus depths positioned in 166 sections along the Burma Arc subduction zone boundary has been investigated. Linear plane fitting and curved surface fitting has been performed on each section. Threedimensional geometric contacts and the extent of subduction are defined quantitatively. Finally, the focal depth distribution is outlined for six typical sections along the Burma arc subduction zone, combining focal mechanisms with background knowledge of geologic structure. Possible dy namic interaction patterns are presented and discussed. This paper provides an elementary method for studying the geometric contact of the Chinese mainland crust with adjacent plates and serves as a global reference for dynamic interactions between plates and related geodynamic investigations.展开更多
基金A subsidiary subject of the National Natural Science Fundation Project No. 9487001.
文摘The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Hangwula structural zone, which was a passive continental margin in the Early Palaeozoic and was transformed into an active continental margin in the Late Palaeozoic;3. the Shalazha structural zone characteristic of a mature island arc; 4. the Nuru-Langshan structural zone, which was a Proterozoic orogenic belt and later evolved into an extensional transtional crust in the Palaeozoic. The above-mentioned tectonic units differ remarkably in sedimentary formations, magmatic rock associations, metamorphism and geochemistry and are bounded by faults between one another.
基金supported by the National Science and Technology Support Plan Project (Grant No.2012BAK19B01-04)
文摘Accurately characterizing the threedimensional geometric contacts between the crust of the Chinese mainland and adjacent regions is important for understanding the dynamics of this part of Asia from the viewpoint of global plate systems. In this pa per, a method is introduced to investigate the geometric contacts between the Eurasian and Indian plates at the Burma arc sub duction zone using earthquake source parameters based on the Slabl.0 model of Hayes et al. （2009, 2010）. The distribution of earthquake focus depths positioned in 166 sections along the Burma Arc subduction zone boundary has been investigated. Linear plane fitting and curved surface fitting has been performed on each section. Threedimensional geometric contacts and the extent of subduction are defined quantitatively. Finally, the focal depth distribution is outlined for six typical sections along the Burma arc subduction zone, combining focal mechanisms with background knowledge of geologic structure. Possible dy namic interaction patterns are presented and discussed. This paper provides an elementary method for studying the geometric contact of the Chinese mainland crust with adjacent plates and serves as a global reference for dynamic interactions between plates and related geodynamic investigations.
