东昆仑夏日哈木镍铜硫化物矿床成矿岩浆条件:流体挥发份化学组成与碳同位素组成制约

发布时间：2018-03-22 17:44

  本文选题：来源　切入点：碳同位素　出处：《岩石学报》2017年01期 　论文类型：期刊论文

【摘要】：夏日哈木镍铜硫化物矿床是我国东昆仑造山带新发现的全球岛弧环境最大的岩浆镍铜硫化物矿床。早泥盆世镁铁-超镁铁质成矿岩体中不同类型岩石的辉石中流体挥发份化学组成和碳同位素组成表明,流体挥发份总量较低,平均含量为888mm~3.STP/g(STP:标准温度和大气压)。流体挥发份组成以H_2O为主(48mol%),其次为H_2(26%)、CO_2(15%)和CO(5%)。H_2S含量从二辉橄榄岩(10mm~3/g)、橄榄辉石岩(18mm~3/g)到二辉辉石岩(28mm~3/g)逐渐增加,表明岩浆就位结晶演化过程中含硫组分的加入。CO_2的δ~(13)C值(-23.5‰~-5.0‰)位于地壳和地幔值范围之间。CH_4同系物碳同位素组成随碳数具有总体正序、局部反序的分布特征,显示大洋沉积有机质热裂解成因特征。夏日哈木成矿镁铁-超镁铁质岩体流体组分中较低的H2_O含量和较高的H_2含量表明,岩浆演化处于还原性挥发份条件,地幔岩浆源区存在俯冲洋壳沉积有机质,岩浆房围岩的混染和富S流体的加入可能是夏日哈木岩浆镍铜硫化物矿床硫饱和的主要机制。
[Abstract]:The summer Hamu nickel-copper sulfide deposit is the largest magmatic Ni-Cu sulfide deposit in the island arc environment of the East Kunlun orogenic belt in China. Pyroxene midstream of different types of rocks in the early Devonian magnesia-ultramafic ore-forming body. The chemical composition and carbon isotopic composition of body volatiles indicate that, The total amount of fluid volatilization is relatively low, the average content is 888mm / 3.STP: standard temperature and atmospheric pressure. The volatile composition of the fluid is mainly composed of H2O (48mol / g), followed by H226Stud (Co21515g) and CO(5%).H_2S (from 10mm / 3 / g, 18mm / 3g) to 2828mm / 3g / g, respectively, and the content of CO(5%).H_2S increases gradually from 10mm / g to 2828mm / 3g / g, and the content of CO(5%).H_2S increases gradually from 10mm / g to 2828mm / 3g / g, and the content of CO(5%).H_2S increases from 10mm / g to 2828mm / g / g, respectively. The results show that the sulfur components of the magma in the process of crystallization evolution of the magma have the distribution characteristics of total positive sequence and local inverse sequence with the addition of sulfur component. COSP _ 2 (未 -23.5 鈥，

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