摘要
为进一步揭示黑龙江大砬子铁多金属矿床的地质特征及矿床成因,分析与大砬子矿床成矿关系密切岩石的主微量、稀土元素地球化学特征,研究其成矿阶段元素迁移规律,厘定该区蚀变分带地质特征。结果表明:与成矿密切的花岗岩属高钾钙碱性花岗岩,富集Rb、Th、U等大离子亲石元素,亏损Nb、Ta、Ti等高场强元素,具有俯冲带岩浆岩的地球化学特征;矽卡岩化经历了由碱性氧化到酸性还原的过渡,成矿发生于碱性氧化环境;可厘定的蚀变类型有花岗岩→角岩→矽卡岩,大理岩→矽卡岩;元素迁移规律显示角岩→矽卡岩元素迁移最为明显,与成矿关系最为密切。结合矿床地质特征与区域地质演化,认为大砬子铁矿床的形成与古太平洋板块的俯冲挤压造山后期的伸展环境有关,为矽卡岩型矿床。
This paper is an effort to further reveal the geological characteristics and genetic mechanism of the Dalazi iron-polymetallic deposit in Heilongjiang.The study works by analyzing the geochemical characteristics of major and trace rare earth elements in the rocks closely correlated with the mineralization of Dalazi deposit,investigating the element migration patterns during the mineralization stages;and defining the geological characteristics of the alteration zoning in this area.The research results indicate that the granite closely related to mineralization belongs to the high-potassium calc-alkaline series granite,which is enriched in large ion lithophile elements such as Rb,Th,U,and depleted in high field strength elements such as Nb,Ta and Ti,and has the geochemical characteristics of subduction zone magmatic rocks.Skarnization experiences a transition from alkaline oxidation to acidic reduction,and mineralization occurs in an alkaline oxidation environment.The alteration types identified are granite→hornfels→skarn,marble→skarn;the migration laws of elements shows that element migration is most obvious in the hornfels→skarn,which is most closely related to mineralization.Combining the geological characteristics of the deposit with the regional geological evolution,it is determined that the formation of the Dalazi iron deposit is related to the extensional environment of the late subduction and compression orogeny of the ancient Pacific plate,and it is a skarn-type deposit.
作者
张富程
丁雪琪
杨帅
李健唐
Zhang Fucheng;Ding Xueqi;Yang Shuai;Li Jiantang(Haikou Marine Geological Survey Center of China Geological Survey,Haikou 570100,China;Haikou College of Economics,Haikou 570100,China)
出处
《黑龙江科技大学学报》
2025年第4期565-574,共10页
Journal of Heilongjiang University of Science And Technology
基金
中国地质调查局地调项目(DD20230619)。
关键词
地质特征
地球化学特征
矿床成因
大砬子矿床
geological characteristics
geochemical characteristics
ore genesis
Dalazi deposit
