摘要
二叠纪-三叠纪之交生物灭绝主要受古环境演变的控制.然而,古地理、古构造背景和生物自身因素(如生物的生理特征)也影响着生物的演化规律及空间分布.从沉积学、放射虫古测深以及生物组合等方面对扬子海盆及其周缘的古地理特征进行了详细研究,重建其古地理和古构造背景,为华南古-中生代之交生物和环境演化的全球可对比性提供了古地理依据.研究表明:(1)扬子海盆北缘,从南往北,水体逐渐变深,面向东秦岭-大别深海;扬子海盆南缘深水盆地,从北往南,水体也是逐渐变深,面向古特提斯洋盆.扬子海盆边缘面向广海表明扬子海盆二叠纪末生物和环境演化具有区域上广泛的代表性甚至全球意义.(2)扬子海盆北缘盆地的古水深普遍小于南缘深水盆地的古水深.(3)华北板块与华南板块的最终碰撞发生在二叠纪以后;钦防地区晚古生代为洋盆环境(古特提斯的分支小洋盆),该洋盆一直延续到二叠纪末甚至三叠纪,因此,扬子和华夏古构造体系西南段的最终碰撞和拼合可能发生在二叠纪末甚至三叠纪.
The Permian-Triassic mass extinction was controlled by the palaeoenvironment evolution.However,the palaeogeographic feature,tectonic setting and biota physiological feature also influenced the biotic evolution and their spatial ranges.To reconstruct the palaeogeographical features of the basin,we conduct research on the latest Permian sedimentary feature,radiolarian palaeobathymetry and biota of northern and southern parts of Yangtze Basin,It is proposed that the water depth increased towards northern margin of the basin in the north part of the Yangtze Basin,facing the northern margin of the Yangtze Basin and opening to the eastern Qinling-Dabie deep sea;whereas the water depth increased towards southern margin of the basin in the south part of the Yangtze Basin,facing the southern margin of the Yangtze Basin and opening to the Paleotethys Ocean.The evolution of organisms and environments of the Yangtze Basin during the Permian was linked to the counterpart inthe Paleotethys and is therefore,not a local episode separated from other parts of the world,and rather representative in a regional scale or even in the world.In addition,the water depth in the north part of the Yangtze Basin was shallower than that in the south part.It is also suggested that the collision between the north part of South China Block and the North China Block happened after the End-Permian.The final collision between the Yangtze Block and the Cathay Accreting Block happened at the end of the Permian or even Triassic along the southwestern part,based on that it was deposited in a setting of ocean during the Late Palaeozoic in the area of Qinzhou-Fangcheng and such a setting continued to the End-Permian or even to the Triassic.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2015年第2期275-289,共15页
Earth Science-Journal of China University of Geosciences
基金
国家自然科学基金项目(No.41372030)
中国地质调查局项目(Nos.1212011220529
12120113012500)
关键词
沉积学
放射虫动物群
生物组合
古地理
二叠纪
扬子海盆及其周缘
sedimentology
radiolarian
biotic assemblages
palaeogeography
Permian
Yangtze Basin and its marginal region
