湘中涟源凹陷测水煤系顺层构造与滑脱构造研究

On Ceishui Formation's Bedding Structure and Decollement Structure of Lianyuan Depression in Central Hunan Province

区内顺层构造及滑脱构造具有多层次、多级别、多时代的迭加组合特征。加里东基底与沉积盖层的不整合面是最大和最深层次的顺层构造 ,测水煤系及其上下地层之间也存在着三个低序次的顺层构造。滑脱构造先北西向推覆 ,后南东向滑覆 ,前者主要表现为前部倾向南东的叠瓦状逆冲断层系及东缘拉张正断层 ,构成挤压体制下逆冲推覆构造 ,后者主要表现为前部倾向北西的逆冲断层系及西缘拉张正断层 ,构成伸展体制下重力滑覆构造。

The Bedding Structure and the Decollement Structure have the combined properties of multi-levels, multi-ranks and multi-eras. The depositional unconformity between Caledonian base and the deposit capping is the biggest and deepest Bedding Structure, and there also exist three secondary Bedding Structures between the Ceishui Formation and the neighboring strata. The Decollement Structure contains two parts, napping northwestly and gliding southeastly respectively. The former is mainly an obducting napping by compression with the front dipping into the imbricate thrust lying in the southeast and the extension of normal fault in the east borders, whereas the latter is mainly an gravity gliding structure by extension with the front dipping into the thrust in the northwest and the extension of normal fault in the west border.