西北太平洋边缘及特提斯北缘中生代盆地成因(上)

Tectonic Evolution of Mesozoic Basins on the Northwest Pacific Margin and the North Tethys Margin(I)．

西北太平洋边缘及特提斯北缘中生代盆地在早－中三叠世、早－中侏罗世和早－中白垩世处于裂谷期，前者残存的构造样式表明裂谷作用源于右行剪切拉分，后者的构造样式表明裂谷作用源于被动拉伸兼左行剪切。后裂谷期以中性环境为主并发生热沉降。在裂谷期末和后裂谷期末均发生脉动式剪切挤压作用．中生代盆地的裂谷作用可能源于亚洲大陆相对太平洋板块和北特提斯板块向北漂移，分别在后两者之间产生右行剪切和拉张。脉动式挤压可能源于亚洲大陆板块转向相对南移（或太平洋板块和北特提斯板块相对亚洲大陆北移），造成西北太平洋边缘沿北北东－北东向左行剪切。中新生代盆地应变－时间曲线可能具有分形分布特征。

： Tectonic evolution of Mesozoic basins on the northwest Pacific margin and north Tethys margin can be divided into three first-order rifting stages： Early-Middle Triassic， Early-Middle Jurassic and Early-Middle Cretaceous rifting stages， and corresponding post-rifting stages for the other times． Pulse movements happened episodically between these stages． The basins in northwest Pacific margin and north Tethys margin episodically rifted from dextral pull-apart and from extension respectively， on basis of their tectonic styles． Such dextral pull-apart rifts and passive extensional rifts were possibly caused by north drift of Asia continent relative to Pacific plate and north Tethys plate． When Asia continent shifted southward relative to Pacific plate and Tethys plate， while the tectonic movements occurred， the northwest Pacific margin was sinistrally sheared along NNE-NE trending faults and the north Tethys was normally compressed in NE direction． The curve of tectonic strain vs． time was possibly with characteristics of Fractal Geometry．