摘要
笔者等根据近年研究,认为新疆东准噶尔卡拉麦里地区晚古生代板块构造的演化,大致分为几个阶段:早泥盆世初,早古生代晚期形成的陆壳拉张,分裂成卡拉麦里有限洋盆;早泥盆世晚期,该洋盆开始聚敛收缩,早石炭世初洋盆闭合,两侧陆块连接;陆块连接带上发育由洋盆转化形成的陆间残余海盆;早石炭世末期,发生强烈褶皱造山运动,把已经连接的陆块最后焊接成一个板块。此后,该区进入板内演化时期。
This paper systematically discusses the evolution of the late Paleozoic plate tectonics in the Karamaili area, East Junggar, Xinjiang. Based on many new data combined with the previous 1/200,000 regional geoIogical surveys, the following late Paleozoic plate tectonic units may be distinguished from north to south in the area:the Yemaquan continental block (YCB), the Karamaili suture (KS) and Junggar continental block (JCB).
The Yemaquan block consists mainly of the Ordovician (?) to Middle Silurian folded basements and the Late Silurian to Early Devonian covers. The late Early Devonian to early Early Carboniferous pericontinental volcanic arc is developed in the southern part of the block.
The basement of the Junggar block has not been clear, and is probably Precambrian in age. During the Devonian the block had uplifted and undergone denudation. From the beginning of the Visean the block was once invaded by seawater, and from the Permian to the present it sank to form the ancient basement of the Junggar basin.
The Karamaili suture is composed of Early Devonian Ophiolites and Middle Devonian fore-arc sediments, overlain disconformably by the Visean to Namurian intercontinental relict sea-basin sediments.
The features of the post-collisional magmatism are summarized briefly and discussed.
Finally, the evolution of the late Paleozoic plate tectonics of the area is discussed. It involved five stages: (1) extension and splitting of the plate, (2) convergence and contraction of the restricted Karamaili oceanic basin, (3) formation of the intercontinental remnant sea basin, (4) welding and orogeny of the connected blocks, and (5) intraplate evolution.
出处
《地质论评》
CAS
CSCD
北大核心
1990年第4期305-316,共12页
Geological Review
基金
国家305项目V_(13)课题
