【摘要】 玢岩型铁硫矿床是长江中下游地区重要的矿床类型,与隐伏闪长玢岩具有密切的成因联系,研究赋矿闪长玢岩的地球化学特征,对探讨玢岩型铁硫矿床的形成及演化、指导深部找矿具有重要意义。文章以庐枞盆地泥河玢岩型铁硫矿床赋矿闪长玢岩为研究对象,在对钻孔详细观察的基础上,研究赋矿闪长玢岩的岩石地球化学特征。该赋矿闪长玢岩具有中高硅含量,高钾富碱,低钛,高铝,富集Sr、K、Rb、Th、Ce等大离子亲石元素,亏损Nb、Ta、Ti、Zr、Hf等高场强元素,属于橄榄玄粗质系列岩石。结合Sr-Nd同位素特征,推测岩浆源区可能为富集型岩石圈地幔,分离结晶与同化混染共同影响岩浆的演化过程。更多还原

【Abstract】 Porphyry-like type iron deposits are one important type of polymetallic deposits in the Middle-Lower Reaches of Yangtze River,and have genetic relationship with concealed diorite porphyrite.The geochemistry study of ore-bearing diorite porphyrite is of significance for investigating deposit genesis and deep exploration.This study carried out lithogeochemical analysis of the ore-bearing diorite porphyrite in conjunction with detailed observation of drilling cores.The ore-bearing diorite porphyrite of the Nihe iron deposit is characterized by high SiO2,K and alkali,low TiO2,relatively high in LILEs such as Sr,K,Rb,Th,Ce,and depleted in HSFEs such as Nb,Ta,Ti,Zr,Hf,suggesting that it belongs to shoshonitic rock.Based on the Sr-Nd isotopic features,it can be inferred that magmatic source region should be enriched mantle,and evolution process of the magma was affected jointly by assimilation and fractional crystallization.更多还原