| 论角砾／网脉-斑岩型金矿 |
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| 引用本文：.1999.A Discussion on Breccia/Stockwork-Porphyry Type Gold Deposits[J].Mineral Deposits,18(1):29~36 |
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| 基金项目:博士点基金( 97018706) |
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| 中文摘要:斑岩型金矿可分为伴生/共生-斑岩型、角砾／网脉型和单脉／网脉-斑岩型3类。角砾岩筒及其内部构造裂隙、角砾岩筒与围岩的接触带构造、与角砾岩筒有成生关系的断裂构造是斑岩型金矿的重要控矿构造。其由角砾状和网脉状矿石组成，两者又难以划分开，故称角砾／网脉-斑岩型金矿。我国本亚类斑岩型金矿中，往往伴有冰长石化（团结沟、义兴寨、祁雨沟等矿床），个别矿床伴有明矾石化（紫金山矿床）．同外同类斑岩型金矿中罕见报道，反映我国此亚类斑岩型金矿的特殊性。 |
| 中文关键词:斑岩型金矿分类，角砾岩筒控矿，角砾/网脉-斑岩型金矿，冰长石化，明矾石化 |
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| A Discussion on Breccia/Stockwork-Porphyry Type Gold Deposits |
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| Abstract:Porphyry gold deposits constitute the thrid most important type gold deposits in China, which have their unique characteristics. Three subtypes can be identified, i. e., associated/porphyry subtype, vein-stock work-porphyry subtype and breccia/stockwork-porphyry subtype. As far as independent porphyry gold deposits are concerned, the third subtype is most important. Breccia/stockwork-porphyry gold deposits are temporally, spatially and genetically related to intermediate-acidic hypabyssal or subvolcanic intrusives. In the large-size Tuanjiegou gold deposit, 90% proved gold reserves are distributed in a breccia pipe within the plagioclase granitie porphyry. The large-size Zijinshan Cu-Au deposit is controlled by a volcanic conduit 700 m in diameter, which is composed of cryptoexplosion breccia. Dacitic cryptocxplosion breccia tuff and intermediate-acidic subvolcanic rocks. Orebodies were discovered in the active fractures in the inner part of the exocontact zone of the breccia body. The small-size Qibaoshan Cu-Au deposit is developed in the breccia pipe, with the breccia components being granodioritic porphyry, quartzdioritic porphyrite and pyroxene monzonitic porphyry. The Qiyugou and Pibagou small-size gold deposits occur in breccia pipe in quartz porphyry and the surrounding active fissures. On the bassis of geological and petrographical studies, these intermediate-acidic intrusives are considered as subvolcanic hypabyssal stocks. Orebodies are directly controlled mainly by the cryptoexplosion breccia pipe and secondarily by related fractures, which are composed of breccia and stockwork ores. In the above-mentioned porphyry deposits, alunite was discovered in Zijinshan while adularia was found in Tuanjiegou, Qiyugou and Yixingzhai. In the large-size deposits, alunite or adularia alteration is in the planar and annular form. The existence of alunite or adularia in the breccia/stockwork-porphyry gold deposits is an important factor in understanding the geological mode of occurrence of adularia-sericite and alunite-kaolinite alteration mineral assemblages and the relationship between the epithermal porphyry type and the epithermal vein type gold deposits and in elucidating their genesis. |
| keywords:Classification of porphyry gold deposits, ore-controlling breccia pipe, breccia/stockwork-porphyry gold deposit, adularization, alunitization |
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