摘要
山东淄河断裂带由近于平行的3~5条断裂构成,具多期活动性,经历了早期左行压扭为主-中期张性为主-晚期右行压扭为主的发展阶段:早期平推扭动所产生的层间裂隙和层间空隙为成矿热液交代沉淀提供了有利空间,铁矿化及矿体形态受断裂构造和层间构造的严格控制;中期的张性构造活动引发了地壳深部岩浆热液活动,提供了矿质来源;淄河式铁矿形成后,晚期右行压扭构造活动使矿体遭受破坏,断裂带南端被EW向断裂切截,该断裂带是淄河地区的控岩控矿构造,不仅提供了含矿热液上升运移的通道,而且造就了矿液沉淀储集的空间。淄河式铁矿主要赋矿层位为寒武-奥陶系九龙群炒米店组中下部及马家沟群北庵庄组和五阳山组,岩层钙质含量高、硅质含量低、性脆、裂隙发育,易于交代成矿,形成品位高、规模大的矿体(床)。淄河断裂带转弯并有分支断裂复合或次生断裂及与其交叉切割的NW向断裂交会处,不仅控制着燕山晚期闪长岩体的分布,而且是形成中低温热液交代充填-风化淋滤型(淄河式)铁矿大矿、富矿的有利部位。
The Zihe fault zone in Shandong Province consists of nearly parallel 3 to 5 faults.It has multiple periods of activity,and has experienced the development of early left lateral compresso-shear stage,to middle extensional stage,and final right lateral compresso-shear stage.(1)The interlaminar fissures and interlaminar voids generated by the early flattening and twisting provided a favorable space for the ore-forming hydrothermal metasomatic precipitation.Iron mineralization and ore body form were strictly controlled by fault structure and inter-layer structure.(2)The middle extensional structure triggered the deep magmatic hydrothermal activity of the crust and provided the mineral source.(3)After the formation of the Zihe iron ore,the late right lateral compresso-shear activity damaged the ore body,and the southern end of the fault zone was cut by the EW-trending fault.This belt is an important rock-controlling and ore-controlling structure in the Zihe area,which not only provides a channel for the ascending and transporting of the ore-bearing hydrothermal fluid,but also creates a space for sedimentation and storage of the ore fluid.The main ore-bearing strata of the Zihe-type iron deposit are the middle and lower parts of the Chaomidian Formation of the Cambrian-Ordovician Jiulong Group,and the Beianzhuang Formation and the Wuyangshan Formation of the Majiagou Group.The rock layer has high calcareous content,low siliceous content.It is brittle and cracked,favoring metasomatism and mineralization,thus forming an ore body(deposit)of high grade and large scale.The turning of the Zihe fault zone and the branch fault recombination,or secondary fault and its part intersected by the NW-trending fault,not only control the distribution of the late Yanshanian diorite,but also become a favorable place to form large,rich deposits of the medium-low temperature hydrothermal metasomatic filling-weathering leached(Zihe type)type.
出处
《地质学刊》
CAS
2019年第4期532-541,共10页
Journal of Geology
基金
中国地质调查局国土资源大调查之基础调查类项目“山东1∶25万淄博市幅区调修测”(10101137001)
“华北重要经济区带资源与环境地质背景调查及数据更新”项目之子项目(200113000026)
“山东省矿产资源潜力评价”(1212010881607)
关键词
断裂带
控岩
控矿
淄河式铁矿
山东
fault zone
rock-controlling
ore-controlling
Zihe-type iron ore
Shandong
