中国东北地区二叠纪生物混生机制讨论

生物混生现象是指不同生物古地理区系的生物出现于同一地区的同时代地层中，表明它们曾同时或略为先后地生活或埋藏在一起。中国东北地区早二叠世时期出现明显的北方冷水动物群（归属北方大区准噶尔－兴安生物省）与特提斯暖水动物群（归属特提斯大区内蒙－吉林生物省）的混生现象；晚二叠世出现安加拉植物群（Ａｎ－ｇａｒａｆｌｏｒａ）与华夏植物群（Ｃａｔｈａｙｓｉａｎｆｌｏｒａ）的混生。对于这些生物混生的机制及阻隔生物迁移扩散的障岩的详细研究，对于解决中国北方二叠纪古海盆性状和南北板块最终缝合带的位置等问题具有重大意义。

A DISCUSSION ON THE PERMAIN BIOTA MIXTURE IN NORTHEAST CHINA

On the mixture of the cold and warm water fauna At the early stage of Early Permain, the mixture of the cold and warm water fauna on the northern margin of North China plate indicated that the collision of North China plate with Xing'an, Sonnen, and Jiamusi massifs had finished earlier and the collision area was an intercontinental residule sea basin. There were two factors that colonial coral and Tethys fusulinidea did not pass through the boundary line of Changchun Yanji. One is paleoclimate factor, to the south of the line, it was a transmission region of the living of colonial coral and Tethys fusulinidea, and also of numerous small simple coral and thicken shell brachiopda; but to the north of the line, it was north temperate zone with colder sea water, which was not suit for the living of colonial coral and Tethys fusulinidea, but for small simple coral and thicken shell brachiopda widespread living. Another one is that the line was an island arc bathypdagic zone as a collission zone between the south and north massifs obstructed colonial coral and Tethys fusulinidea spreading from south to north. 2.On the mixing pattern of the Cathaysian flora and the Angara flora With the research of the paleobiogeography and distribution of the biota assemblages, the authors hold that the seperation of the Cathaysian flora and the Angara flora resulted from the paleo mountain system between them and their paleoclimate differences, and their mixture later resulted from the warming of paleoclimate during Early Permain Late Permain and from the paleogeographical zone moving north.