淮南煤田逆冲叠瓦扇构造系统

THRUST IMBRICATE FAN TECTONIC SYSTEM OF HUAINAN COAL FIELD

淮南煤田推覆构造发育于淮南复向斜南、北两翼。南缘推覆构造更为强烈,规模亦大,系由一系列走向近 EW,向 S 倾斜的逆冲断裂组成。剖面上各断裂上陡下缓,向下逐渐归并于统一的滑脱面,从而构成上叠式逆冲叠瓦扇构造。滑脱面在倾向上及走向上均呈波状变化。北缘的反向逆冲叠瓦扇可能是在南缘逆冲推覆的构造作用下被动产生的。这在宏观、微观及超微观分析中都清晰地得到显示。然而,它们是近于同时形成的。这样就构成了淮南煤田的前缘止于反向断层的逆冲叠瓦构造系统。

The nappe structures of Huainan coal field are developed on both south and north fringes ofHuainan synclinorium,especially on the south fringe,The south fringe nappe is stronger and greater,andcomposed of serise of thrust faults which are of trend about EW and tendency towards S.On the section ofthe thrust,all of the faults presented upper steep and lower gentle and gradully combined to the samedetachment fault at the lower position and constituted an overstep propagation thrust imbricate fan.Thedetachment fault is wavering both on the trend and tendency.The backthrusts on the north fringe might beproduced passively under the tectonic action of the south fringe thrust.The results of macroscopic,microcosmic and super-microcosmic analyses all showed clearly that the scal and strength of deformation,andthe enviroment of strain of the south fringe thrust are all higher than those of the north fringe thrust.Butthey are formed near at the same time.Thus this,the thrust imbricate tectonic system with the leading edgeceased at backthrusts is formed.