北山造山带的基本成矿特征
Main Metallogenic Characteristics in the Beishan Orogen
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摘要: 北山造山带位于塔里木板块北部边缘,属于古亚洲构造区南带天山-兴安造山带中西段。区域地壳结构有基底结晶岩系(新太古界)和褶皱岩系(中新元古界),盖层为古生界,自上震旦统至二叠系基本连续出露。构造形态为一系列总体东西向向北突出的弧形大断裂分割的断块,断块内褶皱强烈。岩浆活动频繁,岩石类型复杂,花岗岩类可明显分出S、I型,基性-超基性岩可分出铁质和镁质,火山岩具裂谷火山岩特征,具有数条蛇绿杂岩,表明具有较好的成矿环境。本区矿床可分7大类:1与中酸性侵入岩有关热液矿床;2与火山岩有关热液矿床;3沉积变质矿床;4沉积矿床;5喷气沉积-改造矿床;6与基性-超基性岩有关岩浆矿床;7热液再造矿床。根据本区的成矿地质背景,包括地质条件、矿床分布、矿化分带性、遥感蚀变异常、地球化学异常及地球物理特征等,提出10个找矿远景区。Abstract: The Beishan orogen located along the northern margin of the Talinu massif belongs to thewestern-centralportion of the Tianshan-Xing'an orogen of the Paleo-Asia tectonic domain.The crustal components in the region include: late Archean crystallization basement, middle-late Proterowic fold series and Paleozoic cover of upper Simian to Permian stratigraphic system.Structure is characterized by fault blocks are divided by a series of arc-foam faults in a east-west stretch.In side he blocks, there are intensive folds and active magmatign.Granites can be classified to I-and S-type, andmafic and ultramafic rocks are Ferich and Mg-rich kinds.Volcanicspossess continental rift feature.A number of ophiolite canes have been found in the area.All these indicate an excellentmetallogenic setting.Seven types of ore deposit have been reposted in the area:①interm ediate-acid intrusion-related hydro thermal ore deposit;②volcanic hydrothermal ore deposit; ③meta-sedimentary ore deposit;④sedimentary ore deposit;⑤exhalative sedimentary reworked deposit;⑥basic-and ultrabasic magma-related ore deposit;⑦hydrothermal reworked ore deposit.Tentarget prospecting areas have been pinpointed according to detailed geological work.