河南西南部含恐龙蛋化石盆地沉积及构造特征

SEDIMENTARY AND TECTONIC CHARACTERISTICS OF THE BASINS CONTAINING OOLITHIAS OF DINOSAURS IN SOUTHWESTERN HENAN

位于河南西南部的东秦岭造山带,在后造山阶段形成了一系列NW—SE向的中、新生代地壳表层断陷盆地,堆积了一套类磨拉石红色建造,含有丰富的恐龙蛋化石。盆地两侧或一侧都有长期活动的大断裂控制,具有走滑、逆冲性质。盆内发育不同规模的舒展褶皱或突起,断层以正断层为主,规模较小,方向分散。盆地发展经历了燕山(Ⅲ-V幕)和喜山旋回两个阶段,构造应力场以总体挤压、局部拉伸为特征,且经历了多次挤压、拉张交替转化。

In southwestern Henan,a series of Me sozoic-Cenozoic supracrustal faul t and basins are filled with red molasses-like formation in whic h contain aboundant oolithias of din osaurs,formed in the postorogenic s t age of the east Qinling orogenic belt,and controlled by the great and active NW-SE-trending strike-slip or thrust faults along one or two sides o f the basins.In these basins,there a re wide-opened folds,flexures and normal faults developed under the te ctonic stress fields of compression with local extension or the alternating of transition during the late Yanshan(fromⅢ-V phases)and early Himalayan cycles.