招平断裂带中段深部结构构造——来自地震剖面的证据

The Deep Structural Characteristics under the Middle of Zhaoping Fault Zone—Evidences Coming from Seismic Section Survey

摘要:

玲珑花岗岩岩基东侧的招平断裂带是胶西北矿集区的主要控矿构造之一。布设于招平断裂带中段大尹格庄矿区的地震剖面,揭示了招平断裂带中段深部的结构构造特征，地震剖面显示，玲珑岩基内部有多个类似“拱弧构造”的岩浆侵入形成的弧形界面，由此推测存在2~3期的岩浆活动。剖面显示了3期构造组合样式，第1期为以招平断裂带和宋家河断裂为组合倾向SE的铲式断裂，底部似汇入统一的构造滑脱带；第2期为倾向NW的错断了招平断裂带的反倾伸展断裂；第3期为NE向延伸以花状构造为特征的走滑断裂。前两期反映构造发育处于伸展环境，第3期显示为左行走滑。招平断裂带深部延伸存在分支复合现象，形成由2个主裂面夹持的透镜状岩片。地震反射剖面数据的获得对深刻理解该区域中生代岩浆构造演化过程和深部找矿具有重要的借鉴意义。

Abstract:

Zhaoping Fault Zone is one of the main ore-control faults of the gold concentration areas in the northwestern Jiaodong Peninsula, extending along the east side of Linglong Pluton. The deep characteristics of structures of the middle section of Zhaoping Fault Zone are revealed by high revolution reflective seismic survey section crossing the Zhaoping Fault Zone nearby the Dayingezhuang gold mine. It shows that there are many arch-structures forming by the magma intrusion inside the Linglong pluton which indicates 2-3 stages of magma activities. It also shows 3 kind of tectonic pattern suggesting different tectonic movement stages. The first pattern is listric normal fault composed by Zhaoping Fault and Songjiahe Fault with the same detachment zone in depth which indicates an extension along the direction from NW to SE. The second faults pattern is a series of faults cutting through Zhaoping Fault, dipping to NW, and indicates a little of thrusting movement to SE. The third pattern is a set of strike-slip fault extending from NE to SE, with left–lateral dislocation. The seismic section shows the main fault plane of Zhaoping Fault has a branch in depth, and bounds a lens-like microlithon. The information obtained by the seismic survey is significant to understand the process of magma-tectonic evolution in this area during Mesozoic Era and will be helpful to the exploration in depth.