内蒙古敖汉旗白土营子多金属矿床地质特征及成因探讨

Geological Characteristics and Genesis of Baituyingzi Polymetallic Deposit in Aohan Banner,Inner Mongolia

白土营子多金属矿床位于华北地台北侧大陆边缘的岩浆活动带上,是华北北缘多金属成矿带东端新发现的斑岩型铜钼-热液脉型铅锌银-矽卡岩型铁铜的超大型多金属矿床。北西向F1断裂是该矿床的主要控矿构造,具有继承性和多期活动的特点,黑云母二长花岗岩和钙碱性花岗斑岩均沿F1断裂侵位,花岗斑岩是成矿母岩,斑岩型铜钼矿化主要赋存于花岗斑岩岩株的内、外接触带的硅化+绢云母化带中,热液脉型铅锌银矿化套叠在斑岩型铜钼矿化的外侧,受青磐岩化带控制,具有典型的蚀变分带性和矿化分带性。本文结合最新的勘查成果,对矿床地质特征进行了总结,探讨了矿床成因和成矿模式。其成因主要为斑岩型铜钼-热液脉型铅锌银-矽卡岩型铁铜高中温热液矿床,且有多期、多阶段成矿为特点。

Baituyingzi polymetallic deposit is located in the magmatic activity belt at the continental margin of the north China platform.It is a newly discovered porphyry Cu-Mo,hydrothermal vein Pb-Zn-Ag,skarn Fe-Cu deposit at the eastern end of the polymetallic metallogenic belt in the margin of the north China platform.The NW F1 fault is the main ore-controlling structure of the deposit,with the characteristics of inheritance and mutiperiodic activity.Biotite monzonite and calc-alkaline granite porphyryall all along the F1 fault emplacement.Granite porphyry is the oreforming parent rock.Porphyry Cu-Mo mineralization mainly occurs in the silicide-sericitization belt of internal and external contact zone of granite porphyry.Hydrothermal vein Pb-Zn-Pb mineralization nested in the outer edge of the porphyry Cu-Mo mineralization.The ore body is controlled by propylitization belt,with typical alteration and mineralization zoning.Based on the latest exploration results,this paper summarizes the geological characteristics of the deposit and discusses the genesis and metallogenic model of the deposit.Its genesis is mainly porphyry Cu-Mo,hydrothermal vein Pb-Zn-Ag,skarn Fe-Cu,high-medium temperature hydrothermal deposit,with characteristics of multi-stage mineralization.