【作者】 李同柱；

【导师】 孙传敏；

【作者基本信息】 成都理工大学 ， 矿物学、岩石学、矿床学， 2007， 硕士

【摘要】 近年来，随着地方采矿业和国土资源地质大调查的实施，在扬子地台西缘大渡河谷中段乌斯河——金口河地区的寒武系麦地坪组白云岩中陆续发现一批整合层状铅锌矿床、矿点，比较典型的有乌斯河、宝水溪、牛心山铅锌矿床。我们把这些分布在大渡河谷沿岸的铅锌矿床称之为“大渡河谷式铅锌矿床”。通过对典型矿床的地质特征和常量元素、微量元素、稀土元素、同位素地球化学以及流体包裹体等方面的研究，取得的主要成果如下：在乌斯河矿区，发现了大量的纹层状铅锌矿石。有学者认为其属于“喷流型铅锌矿床”的产物。这些纹层状矿石主要为贫矿石，“喷流型铅锌矿床”可能代表本区铅锌矿的初始沉积富集阶段，更重要的铅锌矿富集成矿应该在“MVT”阶段。铅锌矿床(点)的分布，总体上受南北向甘洛～小江、峨边～金阳和东西向石棉～峨边深大断裂的控制。矿床主要分布于次级背斜和断裂有利部位中。成矿元素Pb、Zn主要来源于基底岩石和盖层沉积碳酸盐岩地层；硫则主要来自地层，为海相硫酸盐的还原产物；成矿流体来源主要为同生沉积水和大气降水。峨眉山玄武岩岩浆的热驱动作用是区内含矿热卤水运移的主要驱动力。早震旦世苏雄组的火山—碎屑岩由于渗透率较大而为成矿流体的大规模侧向流动提供了通道。而含矿层之上的筇竹寺组主要为粉砂岩、含炭粉砂质粘土岩，对成矿流体起到了很好的阻挡作用，使之在麦地坪组合适部位沉淀成矿。通过与典型MVT铅锌矿床地质特征对比，得出区内矿床成因应属MVT铅锌矿床。结合研究区成矿地质条件特征，建立了大渡河谷式铅锌矿床成矿模式。更多还原

【Abstract】 A number of conformable stratiform Lead-Zinc deposits and occurrences have been discovered in recent years along the Dadu River valley on westem margin of the Yangze Craton. The sulfide-bearing blackish siliceous rocks are interbedded in top of dolomite of Lower Cambrian Maidiping Formation. The author names these deposits as Dadu River Valley Style Lead-Zinc deposits.Based on detail field and microscope observation and ore geochemical analyses, the author regard that these deposits are belong to MTV Lead-Zinc deposits and build up the metallogenic model of Dadu River Valley Style Lead-Zinc deposits.Their geological characters include these follows. They are apparently controlled by faults and distributed along deep faults, such as Ganluo-Xiaojiang, Ebian-Jinyang, Shimian-Ebian. Some minerals in the ore are very fine, such as sphalerite, galenite, pyrite, quartz dolomite and so on. Brecciform, stratiform and block structures are their major types. Silicificative, baritive and carbonative mineralization developed. The ores were formed at low temperature (160-200 degrees). Although there are lots of ores of stratiform structure, most of them are lean ore. The rich ores are brecciform and block structures, which were formed by rebuilding of hot brine in the later.The course of deposits-forming is analyzed: Hot Brine was depressed by Emeishan basalt and drenched basement strata and sedimentary cover, then formed material situation brine, that raised along the faults. When these material situation brine moved to Lower Cambrian Maidiping Formation stratum, PbS, ZnS sedimentated and formed Lead-Zinc deposits because of a shelter--Qiongzhusi Formation stratum which is built up by clay rock.更多还原