【摘要】 六盘山-贺兰山一带到底是板块内部的坳拉谷,还是两个板块之间的碰撞带?长期以来一直众说纷纭。笔者认为:阿拉善地块在晚寒武世以前是中朝板块的一部分,晚寒武世开始才脱离中朝板块,使之具有华南古生物区系特征;早古生代晚期阿拉善地块与柴达木、塔里木地块拼合成西域板块。根据已有资料判断,西域板块可能是在晚古生代(289～269 Ma)重新又与中朝板块拼合,从而形成六盘山-贺兰山碰撞带,并发育大量对冲型逆掩断层系,而在后期构造应力场的作用下发生断陷,在六盘山-贺兰山之间形成宁夏断陷盆地,并覆盖大量沉积物。更多还原

【Abstract】 The tectonic attribution of the Liupanshan-Helanshan area, whether it is a within plate aolagogen or a collision zone between plates, has been debated for decades and remains unclear. The author argued that the Alxa block was part of Sino-Korean Plate before the Late Cambrian, however, it was separated from the Sino-Korean Plate since the Late Cambrian, and therefore, shows the characteristics of the southern China paleontography. In the late period of Early Paleozoic, the Alxa, Qaidam and Tarim blocks were assembled and formed the Xiyu(western China) plate. The data available shows that it is likely that the Alxa block and Sino-Korean Plate integrated again in the Late Paleozoic(about 289–269 Ma), which led to the formation of the Liupanshan-Helanshan collision zone and the ramp thrusts systems, and the subsequent fault-depression which is covered by a lot of sediments, and the Ningxia graben between the Liupanshan and Helanshan mountains.更多还原