【摘要】 南盘江盆地在中三叠世时接受了厚达5000m的复理石沉积,而该复理石中保存有丰富的原生沉积构造。笔者等在这些沉积构造中识别并命名了一类新的构造——同沉积挤压构造,并用简单的实验定性地模拟了该类构造的形成机理。这些同沉积挤压构造包括:挤压皱纹、挤压岩枕、挤压裂隙和挤压皱脊,发育于复理石砂岩层的底面或泥岩层的顶面,是相关砂层或泥层沉积后到成岩前复理石盆地遭受挤压收缩的动态记录。根据这些同沉积挤压构造的方向初步判断,南盘江盆地在中三叠世接受复理石沉积的同时受到了SSW—NNE方向的挤压作用,盆地处于挤压收缩阶段。这些构造为复理石盆地的动态演化研究提供了新的证据。更多还原

【Abstract】 There are abundant primary sedimentary structures in the Middle Triassic Flysch , which is up to 5000 m in thickness, in the Nanpanjiang Basin in southwestern China. A new type of sedimentary structures, syn-sedimentary compression structures, is found and distinguished from these structures. The syn-sedimentary compression structures include compression wrinkles, compression sand pillows, compression fractures and compression ridges, which are found on the surfaces of mud units or the bottoms of sand units of the flysch deposits. The formation processes of all these compression structures are qualitatively simulated with dough, and their origin is discussed. All these structures were formed after the deposition and before the diagenesis, recording compression stresses in the sedimentary basin in the Middle Triassic. The orientations of the compression structures indicate that the flysch basin contracted in a SSW-NNE compression during the Middle Triassic. Thus, the syn-sedimentary compression structures can provide new evidences and constraints on the dynamic evolution of flysch basins.更多还原