华夏碰撞造山带

CATHAYSIS COLLISION OROGENIC ZONE

中国东南边缘大陆──华夏地体基底是双层结构，分别由早、中元古代（2．3～1．5Ga；1．4～1．0Ga）地层所组成，华夏地体乃是经历多阶段演化的复杂造山带。大量早元古花岗岩化的发生和侵出（2．2～1．5Ga）是古华夏造山带克拉通化的标志。古华夏地体在1．0Ga后再与扬子古地体斜接碰撞，遂发生大规模深层推覆析离及岩片堆叠，继后又演化为走向韧性剪切滑移。所得PTl轨迹显示造山作用的递进演变过程。华夏地体与中间（南华）地体自中元古代直至早中生代持续发生作用，形成了宏伟而复杂的华夏板缘岩浆带并表现为向板内迁移的规律。边缘岛弧带诸岛群基底岩石地层、年代学均有相似特点，在晚古生代毗连一体，均处于古亚洲大陆的东南边缘，应是华夏古陆的自然延伸。

The basement of the paleo-Cathaysia terrene consists of two tayers: the Lower and Middle Proterozoic Suberathem (2. 3 - 1. 5Ga; 1. 4 - 1.0Ga ). Cathaysia lerrene is a complicated orogenic zone experienced severai periods of evolution. A great deal of granitization occurrence and intrusion of the Lower Proterozoic Subera (2. 2 - 1. 5Ga) is the symbol of cratonization of paleoCathaysia orogenic zone. In 1. 0Ga, the paleo-Cathaysia was collided with the Yangzi Paleo-terrene. Then,a large scale of deep decollement and slate accumulation, which evolved the strike ductile shearing and sliding later, took place. The PTl trace indicates the gradual evolution process of orogenesis. The Counteraction between the Cathaysia and middle (Nanhua) terrene cotinued from the Middle Proterozoic Subera to Mesozoic Era, which caused the splendid and complicated Cathaysia marginal magmatic zone, moving toward the interplat.The basement rock strata and chronological age of the islands in the marginal island arc zone zre quite simllar. These islands, located at the southeast margiln of the paleo-Asia continent, were connectcd into one body in the Upper Palaeozoic Era. They should be the natural extension of the paleo-Cathaysia continent.