摘要
古陆碰撞继之为海洋盆地关闭、山脉隆起和前陆盆地巨厚碎屑岩系的堆积。造山带的前陆地区,前身是被动陆缘,构造上位于比较低的部位,其地质记录可以保存得相对完整。长江中下游地区,是大别造山带的前陆构造带。通过对那里沉积物形成环境,特别是物源区的分析研究,识别出震旦系至下三叠统被动陆缘沉积岩系和中三叠统至中侏罗统前陆盆地沉积岩系,据此推测大别造山带碰撞造山作用发生在中三叠世。早三叠世被动陆缘岩系和前陆盆地堆积物的空间分布,揭示出中朝与扬子两个地块之间的碰撞方式,在长江中下游地区从东到西基本是同时的。
Closure of oceanic basins, uplift of mountain ranges, and accumulation of thick terrigenous clastic sediments in the foreland basin resulted from collision between continental margins. Relatively complete geological records can be preserved in the foreland areas of orogenic belt, which were once a passive continental margin and located at relatively low structural positions. The middle and lower reaches of the Yangtze River are the foreland tectonic belt of the Dabieshan orogen. Through investigation and analyses of sedimentary settings especially the provenience of sediments, the Sinian-Jurassic sedimentary strata exposed in the study area have been recognized as Sinian-Lower Triassic passive continental marginal sequences and the Middle Triassic-Middle Jurassic foreland basin sequences. And then, it is inferred that the collisional orogeny in the Dabieshan orogen took place in the Middle Triassic. The spatial distribution of the Lower Triassic passive continental marginal sequence and foreland basin sequences demonstrates the collisional pattern of the Sino-Korean and Yangtze blocks, indicating that the collision was basically simultaneous from east to west in the middle-lower reaches of the Yangtze River.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2001年第1期25-34,共10页
Acta Geologica Sinica
基金
地质矿产部资助项目(编号9501102)的成果。
关键词
大别造山带
前陆盆地
扬子地块
中三叠世
震旦纪
foreland basin of the Dabieshan orogen
passive margin of the Yangtze block
Middle Triassic collision, collisional pattern
