| 从赋矿岩系岩石类型的多样性论羊拉铜矿的成因 |
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| 引用本文：.2004.A Discussion on Origin of Yangla Copper Deposit in Light of Diversity of Ore_hosting Rock Types[J].Mineral Deposits,23(4):431~442 |
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| 基金项目:国家“十五”科技攻关项目(课题号: 2001BA609A_5) |
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| 中文摘要:通过野外调查和室内工作，将羊拉铜矿床按矿石的矿物成分和组构分 出9种类型，包括矽卡岩型、大理岩型、砂板岩型、角岩型、凝灰质流纹岩型、玄武岩_辉绿 岩型、花岗质碎裂岩_花岗斑岩型、安山岩型和绢英岩型。矽卡岩型矿石是构成矿体的最主 要矿石类型，但在不同矿段可由碳酸盐岩(里农)和凝灰质火山岩(贝吾)两种原岩形成。矿体 在赋矿岩系中有3种产出形态：顺层呈层状_似层状；沿花岗岩与沉积岩接触面呈透镜状；贯 穿岩体和沉积岩呈大脉状。它们均与后期构造密切相关，矿体无确定的顶、底板岩石，围岩 蚀变以矿体为中心呈环带状分布。研究表明，矿床相对赋矿岩系显示出明显的后成性，属于 印支期花岗岩_花岗斑岩与古生代混杂岩通过强烈的接触交代作用形成的矽卡岩型铜矿床。 |
| 中文关键词:地质学 金沙江缝合带 赋矿岩系 矽卡岩 铜矿床 羊拉 云南 |
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| A Discussion on Origin of Yangla Copper Deposit in Light of Diversity of Ore_hosting Rock Types |
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| Abstract:The Yangla copper deposit is located in Jinshajiang suture belt on the eastern m argin of Tibetan plateau. In Triassic, subduction and closure of the Jinshajian g oceanic basin and the associated continent_continent collision led to the form ation of ophiolitic mélange composed of blocks of different ages and various li thologic characters to the west of Zhongza terrane. The Indosinian large_scale m agmatic intrusion caused mobilization and concentration of ore_forming materials contained in the mélanges. Based on field geological investigations and geoche mical ore studies, the authors found that almost all of the rock types occurring in the ore district were involved in the copper mineralization. According to mi neral compositions and ore fabrics, 9 ore types have been recognized, namely, sk arn, carbonate, slate_hornfels, tuffaceous rhyolite, basalt, gabbro_diabase, gra nite porphyry, breccia, and phyllic type. The skarn ore is the most important ty pe and was formed from two kinds of original rocks of carbonate and tuffaceous v olcanite respectively in the Linong and the Beiwu mine segment. The orebodies ge nerally assume 3 modes of occurrence: stratified_stratoid forms along the beddin g of wall rocks, lenses in the contact zones of granite with sedimentary rocks, and large veins penetrating granite and sedimentary rocks. The orebodies have no definite top and bottom rocks. Wall alteration shows zonation around the centra l ore. The mineralization shows obvious epigenetic characteristics and genetical ly belongs to skarn_type copper deposit formed from strong contact metamorphism of Indosinian granites with Paleozoic mélange of Gajinxueshan Group. |
| keywords:geology, Jinshajiang suture belt, ore_hosting rocks, skarn, copper deposit, Yangla, Yunnan |
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