沂沭断裂带中段金矿构造控矿规律研究

Research on the structural ore-controlling regularities of gold deposit in mid-segment of the Yishu River fault zone

通过对沂沭断裂带中段地层产状、岩性、构造节理的野外勘察,室内镜下观察鉴定和样品测试分析,运用最新的大地构造理论对该区成矿背景综合研究,总结该区金矿构造控矿规律。本区金矿的生成具有韧性剪切带的双阶段控金性。其基底韧性剪切带与断裂带属于继承关系。韧性剪切带中并不赋存金矿,而是作为控矿构造,控制矿床的产出状态,而次级构造控制矿床的分布和延伸。矿床主要分布于应力集中构造活动强烈的区域。韧性剪切带控制金矿的规律在于垂向上控制金矿的梯度性。沂沭断裂派生的控矿构造形迹在区域上由西而东表现为韧性-脆韧性-脆性的演化规律(旋回)和倒N字型断裂组合形态,在其伴生的次级断裂带之间也存在有次级旋回,并构成低级序构造组合图像。

The structural ore-controlling regularities in mid-segment of Yishu River fault zone was summarized according to the attitude of stratum,the lithology and the tectonic joint in the field survey,and the microscopically observation,the sample test analysis.The wield tectonic theory was used to research the mineralization background.The metallogeny of gold deposits there can be merotomized two stages which is inheritance relationship between the basement of ductile shear belt and the fault zone.The gold deposit is not occurrented in the ductile shear belt,and the ductile shear belt acts as the main ore-controlling structure and control the attitude of ore deposit.The secondary structure controls the spread and extends of the ore deposit.The ore deposit is located in the stress concentration belt,which is fierce and superposed tectonic activity area.The ductile shear belt ore-controlling regularity is that the gold controlled gradient-like in vertical direction.The ore-controlling structure which derivatives from the Yishu River fault zone shows ductility-transition-brittle evolution rules（geocyclic） from east to west,and the structure combination configuration shows like a fall ＂N＂.Associated structure shows associated geocyclic and constitute law level tectonic association.