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在讨论中国大地構造單位划分之前,应談一下国大地構造的特点。 (1)中国地台北一般地台(如俄罗斯地台、北美地台等)活动,而地槽比一般地槽(如烏拉尔地槽、阿帕拉齐地槽等)稳定。大家都知道,中国地台基底断裂多,沉积盖层厚,在凹陷区常出现梳状和箱状褶皺,在隆起区则出現断裂和岩漿活动,这是一般地台所沒有的。至于地槽如天山、祁连山、秦岭、大兴安岭等則基性和超基性岩较少,断陷較淺,低角度冲断层不多;由于該处地壳粘—塑性較小,不易一下子沉陷,也不易一下子回返完全,故在構造运动和岩浆活动兩方面都具有显著的多轮迴性(采用黄汲清的术語)。
Before discussing the division of tectonic units in China, we should talk about the characteristics of the tectonics of the country. (1) The general stations in Taipei, China (such as the Russian platform and the North American platform) are active, while the geosynclines are more stable than the geosynclines (such as the Ural geosyncline, the Appalachian geosyncline). As we all know, there are many basement fractures in China and thick sedimentary caprocks. Comb-shaped and box-shaped folds often appear in the depression areas. Faults and magmatic activities occur in the uplift areas, which are not generally found in the platform. As for the Trough, such as Tianshan Mountains, Qilian Mountains, Qinling Mountains and the Greater Hinggan Mountains, there are few basic and ultrabasic rocks, shallow faulting and few low-angle thrust faults. Due to the small plasticity of the crust, the crust is not easily subsided, It is not easy to return to complete at once. Therefore, there are significant multiple cycles (using the terminology of Huang Jiqing) in both tectonic movement and magmatic activity.