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已有关于青藏高原隆升的各种构造模型多重视新生代变形而忽略了早期构造变形的限制。本文以三江北段东莫扎抓矿区为研究对象,通过详细的构造-岩相填图,恢复了矿区二叠纪以来变形序列,结合区域资料讨论了变形事件的大地构造背景。研究表明矿区发育中-下二叠统九十道班组灰岩、上二叠统那益雄组碎屑岩、上三叠统结扎群甲丕拉组碎屑岩和上三叠统结扎群波里拉组灰岩4套地层系统,二叠系与三叠系之间为不整合接触,局部被近南北向逆断层代替。北西向逆断层横亘矿区,断层上盘三叠纪碎屑岩和灰岩整体北倾,断层下盘三叠纪岩石被左右两条走滑断层夹持向南挤出。在图面和露头尺度上矿区叠加褶皱明显,南北向剖面上多见紧闭的倾伏褶皱,近东西向剖面上则为开阔水平的斜歪褶皱,表明南北向剖面上观察到的是已被叠加的早期褶皱,为矿区第一期变形,其形成与三叠纪末古特提斯洋盆闭合有关。始新世晚期印-亚大陆碰撞地壳缩短形成矿区第二期构造,即北西向逆断层和褶皱叠加。第三期近南北向逆断层可能形成于始新世末,与印-亚大陆碰撞引起的侧向旋转有关。
Various tectonic models about the uplift of the Qinghai-Tibet Plateau have been given multiple attention to the deformation of the Cenozoic while neglecting the limitations of early tectonic deformation. Based on the detailed tectonic-lithofacies mapping, the deformation sequence of the mining area since the Permian is restored. The tectonic setting of the deformation event is discussed based on the regional data. The study shows that the limestone in the Middle-Lower Permian Jiuduandan Formation, the Upper Yilixiong clastic rocks in the Upper Permian, the Triassic Laminar clastic formations in the Upper Triassic and the Triassic Ligation Polaris Four sets of limestone stratigraphic systems, unconformity contact between Permian and Triassic, are partially replaced by near-north-south thrust faults. Triassic clastic rocks and limestone are generally north-dipping in the fault plate, and the Triassic rocks in the footwall of the fault are extruded southwards by two left-right strike-slip faults. On the plan and outcrop dimensions, the superimposed folds in the mining area are obvious. The tight sagging folds on the north-south profile are more obvious than those on the profile near the east-west, which indicates that the profile observed on the north- The superimposed early fold, the first phase of the mine deformation, the formation of the Late Triassic paleo-Tethys ocean basin closure. Late Eocene Indian-continental collision crust shortened to form the second phase of the mining area, ie, NW-trending reverse faults and fold superimposition. The third near-north-south thrust fault may have formed at the end of the Eocene and was related to lateral rotation caused by the Indian-Continental collision.