投稿时间:2017-07-20
修订日期:2018-06-04
网络发布日期:2018-11-03
中文摘要:近年来,成矿斑岩岩浆的氧化状态对斑岩铜矿床成矿潜力和成矿规模的控制作用受到了矿床学家的广泛关注。文章总结了斑岩型铜矿床成矿斑岩岩浆氧化状态的主要研究方法及各自的适用条件:①钛铁氧化物(钛铁矿-磁铁矿)固熔体的组成,适用于含共生岩浆成因钛铁矿-磁铁矿的斑岩体;②岩石中的Fe3+/Fe2+含量比值,适用于新鲜的熔融包裹体或未发生热液蚀变和地表风化作用的新鲜岩石;③黑云母中的Fe3+、Fe2+和Mg含量,适用于黑云母与磁铁矿和钾长石共生的岩体;④角闪石主量元素含量,适用于温度为550~1120℃、压力 < 1200 MPa、氧逸度(f(O2))为-1≤ΔNNO≤+5的钙碱性喷出岩或浅成侵入岩;⑤锆石Ce4+/Ce3+比值;⑥锆石EuN/EuN*比值,斑岩铜矿成矿斑岩为中酸性岩体,其中锆石普遍发育,因此被广泛用于确定岩浆氧化状态。文章还通过收集中国冈底斯成矿带、金沙江-红河成矿带、中甸岛弧成矿带、环太平洋成矿域和中亚成矿域主要斑岩铜矿床成矿斑岩岩浆氧逸度资料,讨论岩浆演化状态对斑岩型铜矿床成矿作用和成矿规模的控制作用,发现同一成矿带内含矿斑岩的氧化状态明显高于不含矿斑岩,且含矿斑岩的氧化状态与斑岩铜矿床的成矿规模具有正相关性。
Abstract:In recent years, the constraint of magma oxidation state on mineralization potential and scale of porphyry copper deposits has attracted lots of earth scientists' attentions. This paper summarized main methods for estimating magma oxidation state of porphyry copper deposits and their applied conditions. These methods are:① Ilmenite-magnetite oxygen barometer, which is used in the conditions that ilmenite coexists with magnetite and FeTi oxides have homogeneous chemical compositions; ② Whole-rock Fe3+/Fe2+ ratio, it can only be used on fresh melt inclusions or igneous rocks devoid of hydrothermal alteration or surficial weathering; ③ Biotite component, which coexists with magnetite and potassium feldspar; ④ Amphibole oxygen barometer, which is used with calcalkaline volcanic or hypabyssal intrusive rocks with temperatures of 550~1120℃, pressure of 1200 MPa, and oxygen fugacity of -1 ≤ ΔNNO ≤ +5; ⑤ Zircon Ce4+/Ce3+ ratios, and ⑥ Zircon EuN/EuN* ratios, which are recently popularly used, because zircon is a common accessory mineral in intrusions related to porphyry deposits. On these bases, the magma oxidation state data of porphyry deposits in Gangdese, Jinsha river-Red river, Zhongdian island arc, Circum-Pacific and Central Asian metallogenic belts are collected to discuss the constraint of magma oxidation state on mineralization potential and scale of porphyry deposits. In most metallogenic belts, the orebearing intrusions have higher oxidation state than barren intrusions, and the higher oxidation state is also favorable to the formation of large scale porphyry copper deposit.
文章编号:
中图分类号:P618.42
文献标志码:
基金项目:本文得到陕西省教育厅科技计划项目(批准号:14KJ1761)和国家自然科学基金项目(批准号:41403033)的联合资助
引用文本:
张京渤,安芳.2018.斑岩型铜矿床成矿斑岩岩浆氧化状态研究方法综述[J].矿床地质,37(5):1052~1064ZHANG JingBo,AN Fang.2018.Methods for estimating magma oxidation state of porphyry copper deposits: A review[J].Mineral Deposits37(5):1052~1064
图/表