摘要
东秦岭古海洋是一个从晚元古代开始发育,晚志留开始关闭的古海洋。其关闭的后期,华北板块与扬子板块开始拼贴,340Ma基本拼贴结束。古秦岭海洋的北部(华北板块南部)从晚奥陶世起,由原来的被动边缘转化为一具沟、弧、盆体系的活动大陆边缘,而其南部(扬子板块北部)边缘仍为被动大陆边缘。泥盆纪到石炭纪,上述两类大陆边缘拼贴。根据东秦岭造山带内的大型推覆体构造组合及其配置关系、推覆岩片的变质相倒置、推覆岩片内应变标志物特征及其应变参数测量(发育在420—340Ma期间的推覆体)以及前陆盆地(泥盆—石炭纪)的研究,认为华北板块与扬子板块是以仰冲兼右行剪切方式碰撞拼贴。
Eastern Qinling Palaeoocean is one developed in late Proterozoic and closed during Silurian -- Devonian(420 -- 400Ma). At the late stage of closing, collage between the north China and Yangtze plates took place, which did not end until Carboniferous (340Ma) .The northern part of Qinling Palaeoocean ( the southern margin of the north China plate ) was turned into an active continental margin with a system of trench - island arc - back arc basin formed from late Ordovician, but its southern part ( northern margin of Yangtze plate ) remained a passive continental margin. The two kinds of continental margins mentioned above had been collaged from Devonian until Carboniferous.
With the basis of the following informations: the tectonic assemblage and its collacative relations of major nappes; the inversion of metamorphic facies and the characteristics of strain markers within the nappe sheet and the measurements on strain parameters (the nappes developed during 420-340Ma); and the studies of foreland basin, the tectonism of the north China and Yangtze blocks is a collisional collage accompanied by obduction and a dex-tral shearing.
出处
《石油实验地质》
CAS
CSCD
北大核心
1990年第4期353-365,共13页
Petroleum Geology & Experiment
