合肥盆地沉积构造样式与大别造山带的演化历史

The evolution of the Dabie orogenic belt based on the sedimentary styles and tectonic patterns of the Hefei Basin, Anhui

关键词:  合肥盆地  构造样式  沉积特征  大别造山带  构造演化

Key words:  Hefei Basin  tectonic pattern  sedimentary style  Dabie orogenic belt  tectonic evolution

摘要:

对大别造山带的成生演化已有了系统而全面的研究和认识,但对印支运动期后大别山的构造演化却涉及较少,其工作基础是以大别造山带内的地质研究为基础;笔者以大别山北缘合肥盆地的沉积构造样式为研究对象,重点探讨印支运动期后大别山的成生演化历史。在吸收前人对大别山成果的研究基础上,以合肥盆地沉积和构造样式为主线,结合大别山北缘和合肥盆地的诸多地质特征,对中生代以来,大别山至少存在有四次造山运动:分别发生在印支期、燕山晚期、喜马拉雅早期和喜马拉雅中期。四次造山运动的强弱也明显不同:以印支期最强烈,其次为燕山晚期的挤压推覆,而喜马拉雅期的两次隆升运动较弱。四次造山运动的样式也存在明显差异:印支运动表现为自南而北的大规模挤压推覆运动,燕山晚期和喜马拉雅早期则以小规模的挤压运动为主,喜马拉雅中期则以整体升降为主。

Abstract:

The NWW-trending Dabie Mountains lie in the eastern part of the Qinling-Dabie orogenic belt in central China. The formation and evolution of the Dabie Mountains posterior to the Indosinian movement are focused on the basis of sedimentary styles and tectonic patterns of the Hefei Basin, Anhui. There once occurred at least four episodes of orogenesis in the Dabie Mountains from the Mesozoic onwards:Indosinian, late Yanshanian, early and middle Himalayan. These orogenic processes vary greatly in intensity and patterns. The Indosinian orogenic event is conspicuous for the intense and large-scale compression and overthrusting from south to north. This kind of compression and overthrusting persisted in the late Yanshanian except that its scale is relatively small. The early Himalayan orogenic event is represented by the small-scale compression, whereas the overall uplifting and subsidence took place during the middle Himalayan.