蒙古国南部及邻区金属矿床类型及其时空分布特征

Types and Temporal-Spatial Distribution of Metallic Deposits in Southern Mongolia and Its Neighboring Areas

根据金属矿床产出的围岩岩性组合和成矿作用特征,可将蒙古国南部及邻区分布的各类金属矿床(点)划分为6种类型,即(1)斑岩型铜(金)和铜(钼)矿床(点);(2)矽卡岩型锌和银多金属矿床(点);(3)热液脉型钨、锡、稀有(土)金属和银多金属矿床(点);(4)火山岩型铜(锌)和铀矿床(点);(5)沉积岩型铜多金属和铀矿床(点);(6)砂金和铂矿床(点)。在较详细剖析各类金属矿床(点)基本地质特征和时空分布规律的基础上,划分了10处矿化集中区,并且讨论了区域地壳演化与金属成矿作用的关系。研究结果表明,尽管研究区范围内金属矿床(点)成矿作用可从新元古代一直持续到新生代,但是大规模成矿作用发生的时间分别与海西期和印支期构造-岩浆活动高峰期相吻合,是地壳特定演化阶段综合性地质作用的产物。

Located at the convergence place of the Siberia,Kazakhstan,Tarim and North China paleoplates,southern Mongolia and its neighboring areas constitute one of the most important metallogenic provinces in Central and Northeast Asia.Deep faults,Paleozoic-Mesozoic igneous rocks and metallic deposits（ore spots） are well developed in this region.These deposits（ore spots） can be classified into six types in term of their host rocks and metallogenic features,i.e.,（1） porphyry Cu（Au） and Cu（Mo） deposits（ore spots）;（2） skarn Zn and Ag polymetallic deposits（ore spots） ;（3） vein type W,Sn,REE,rare metal and Ag polymetallic deposits（ore spots） related to granitoids;（4） Cu（Zn） and U deposits（ore spots） within the volcanic terrain;（5） U and Cu-polymetallic deposits（ore spots） hosted by sedimentary rocks.On the basis of systematic studies of the representative metallic deposits（ore spots）,ten mineralization concentration districts have been delineated.They includeⅠ-Asgat-Hul Adar Ag-W-REE district,Ⅱ-Boorj-Salhit Cu-Pb-Au district,Ⅲ-Saran Uul-Han Uul Cu-Au-W-Mo district,Ⅳ-Bayangobi Hill Cu-Zn-rare metal district,Ⅴ-Biluut Ovoo-Har Tolgoi Cu-Pb-W district,Ⅵ-Oyu Tolgoi-Tsagaan Suvargar Cu-Au-Mo district,Ⅶ-Tumurtiin Ovoo-Ariin Nuur Zn-W-Mo-Cu district,Ⅷ-Hairhan-Haraat U district,Ⅸ-Salhit-Tsav Pb-Zn-Ag district,and Ⅹ-Ulaan-Dornod U-Pb-Zn-Ag district.The relationship between the crust evolution and the metallogeny can be summarized as follows：（1） Pre-orogenic stage：rift-faulting resulted in the formation of the banded iron formation（BIF） and quartz vein type gold ore spots within the ancient continent;（2） closing stage of the oceanic crust：igneous activities on the sea floor produced Cu-polymetallic deposits（ore spots）;（3） collision and orogenic stage：a number of porphyry Cu（Au） and Cu（Mo） ore spots were formed;（4） Post-orogenic stage：W,Zn,Sn,REE and rare metal deposits genetically related to the emplacement of crust-derived calc-alkaline and alkaline intrusions.Systematic geological investigations into mineral resources of this region indicate that wall rocks of these metallic deposits vary from place to place,but most of them show an intimate relationship with the Hercynian and Indosinian tectonism and magmatism.Geological and geochemical features of these ore deposits have attracted the attention of geologists both in China and abroad.An integrated analysis of the geological settings as well as geological and geochemical features of these deposits is likely to greatly upgrade our understanding of the ore-forming processes of the ore deposits.Meanwhile,the genetic model and mineral exploration criteria of these metallic deposits can also be used during the comprehensive evaluation of the concealed metallic deposits in southern Mongolia and its neighboring areas.