南盘江盆地中三叠统复理石中的同沉积挤压构造——一类新的沉积构造的归类、命名和构造意义探讨  

Syn-sedimentary Compression Structures in the Middle Triassic Flysch of the Nanpanjiang Basin, SW China

作　　者：吕洪波[1] 章雨旭[2] 夏邦栋[3] 方中[3] 周伟明[3] 彭阳[2] 吴智平[1] 李伟[1] 

机构地区：[1]石油大学(华东)地球资源与信息学院,山东东营257062 [2]中国地质科学院地质研究所,北京100037 [3]南京大学地球科学系,210093

出　　处：《地质论评》2003年第5期449-456,T001,T002,共10页Geological Review

基　　金：石油大学人才引进基金(编号 Y020109)

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。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.

关 键 词：南盘江盆地 中三叠统 复理石 同沉积挤压构造 沉积构造 挤压皱纹 挤压岩枕 挤压裂隙 挤压皱脊 

分 类 号：P544.4[天文地球—构造地质学]