摘要
莱州北部的金矿主要受三山岛和焦家两大断裂控制,断裂内发育诸多的糜棱岩、SL构造岩,石英丝带（L线理）、旋转碎斑和S面理,宏观、微观特征都证实其属于脆—韧性剪切带。研究证明,韧性剪切作用发生在郭家岭岩浆结晶分异的脉岩侵入之后,其时间推测约在126~122 Ma之间。当被主成矿期含金热液充填交代后,糜棱岩、SL构造岩相应形成浸染状黄铁绢英岩化矿石和脉状黄铁绢英岩化矿石。韧性剪切作用的深度较大,推测这2条脆—韧性剪切带约在地下5 500 m的深度交会。沂沭断裂带东侧的次级构造——早白垩世形成的NE向脆—韧性剪切带与郭家岭花岗岩的复合部位,是形成世界级蚀变岩型金矿的最佳部位。
Gold mines in the northern part of Laizhou City are mainly controlled by two major fractures,the San- shandao and Jiaojia fault zones.The mylonite and SL teetonite in these two fault zones,and the macro and micro characteristics, such as quartz ribbon （L lineation）,rotational porphyroclast and S foliation,all confirm that they be- long to the brittle-ductile shear zone.Studies have shown that the ductile shearing occurred after the intrusion of the fractional crystallization dykes from the Guojialing magma,and the time was speculated about in the 126-122 Ma. The mylonite and SL tectonite correspondingly formed into disseminated and veined pyrite phyllic ore,under the filling and metasomatism of gold-bearing hydrothermal of the main mineralization.Ductile shearing of these two fauh zones went a great depth,and was speculated to be intersected at the depth of 5 500 m. The composite parts between the Guojialing granite and the NE brittle-ductile shear zone,the eastern secondary structure of Yishu fault zone,formed in the Early Cretaceous,is the best position for the formation of the world-class alteration rock-type gold deposits.
出处
《黄金科学技术》
2012年第4期26-32,共7页
Gold Science and Technology
关键词
NE向脆—韧性剪切带
糜棱岩
SL构造岩
蚀变岩型金矿
胶西北
NE brittle-ductile shear zone
Mylonite
SL tectonite
Alteration rock -type gold deposit
NorthwestJiaodong
